Pumps/Inflation

Origin-8's Air Surge 2-Stage Frame Pump features a large, telescoping barrel that inflates tires quickly with its simple Presta/Schrader valve head. You'll love the great, ergonomic T-handle and convenient mounting bracket.

Blast off with Planet Bike's Airship 2.0 CO2 Bike Tire Inflator. It's lightweight, strong and easy to use. Stash it in your bike bag or jersey pocket and away you ride. - Lightweight aluminum design stores cartridge and protects from cold cartridge when in use - Auto head fits both Presta and Schrader valves - Accepts 16g threaded and non-threaded cartridges - Includes one 16g threaded CO2 cartridge - Small size fits in saddle bag or jersey pocket - Length: 130mm - Weight: 123 grams

Deluxe steel floor pump – Metallic Grey Make sure you ride in comfort with the correct tire pressure. Planet Bike's redesigned STX floor pump has a big 3" integrated gauge and the Auto Head fits both Presta and Schrader valves. It’s engineered for smooth and efficient inflation. - Rugged steel barrel, plunger, and base - Anatomically designed handle for comfortable air compression - Auto Head fits both Presta and Schrader valves - Oversized 3 inch 160 psi dial gauge - Pressure rated to 200 psi - Needles included for pumping up sports balls - Large steel base for stability - Rebuildable - Height: 27”

Composite and steel floor pump – Arcade White A strong and dependable pump belongs in every garage or basement. Our redesigned Comp floor pump features a big 3" integrated gauge, steel barrel and the Dual Head for Presta and Schrader valves. With included sport ball needles and classic good looks, it’s designed for smooth, efficient and accurate inflation. - Super-tough steel barrel and plunger with a composite base - Anatomically designed handle for comfortable air compression - Dual Head fits both Presta and Schrader valves - Oversized 3 inch 160 psi dial gauge - Pressure rated to 200 psi - Needles included for pumping up sports balls - Large base for stability - Rebuildable - Height: 25”

Big volume barrel while Dual-Action (DA) doubles volume with each stroke and inflates tires up to pressure fast. Integrated dust cap keeps pump head clean and thumb lock lever insures air-tight seal. Specs - HEAD: Presta / Schrader / Dunlop with integrated dust cap - BARREL: Aluminum - THUMB LOCK / HANDLE: Plastic - CAPACITY: 60 psi / 4 bar - VOLUME PER STROKE: 81.4 cc (pull + push) - SIZE: 22.3 x 4.6 x 3.4 cm / 8.8” x 1.8” x 1.3” - WEIGHT: 126 g / 4.44 oz Added Features - Dual-action pumping head - Side mount bracket

Lezyne's convenient Twin speed Drive CO2 inflator is compact and lightweight. Its aluminum head is compatible with both Presta and Schrader valves, and uses a simple twisting action for easy inflation. And, it accepts all threaded CO2 cartridges.

Prestacycle's newest version of the Presta Head Gasket uses Urethane Elastomer. It’s softer and stronger. It lasts more than 5 times longer, gives a better seal and flexes to work anywhere along the Presta shaft for better tubeless tire application.

CO2 replacement cartridges Planet Bike's line of CO2 replacement cartridges make tire repairs quick and easy. - Our CO2 cartridges work in Planet Bike inflators as well as most competitors' inflators - Planet Bike cartridges are tested to the highest standards for durability, safety and reliability. They contain pure CO2 with no oils or contaminants. - Note - unable to ship CO2 to Canada - 100% recyclable steel cartridges - All threaded cartridges are compatible with Air Kiss, Red Zeppelin, Red Zeppelin 2 & Air Smith CO2. - All 16g cartridges are compatible with the Airship 2.0.

Upgraded and redesigned for Year 11, Lezyne's ABS1 Pro further advances our classic Flip-Thread Chuck system. It features a 90° design for enhanced function and usability. The highly durable construction is built using machined aluminum and composite matrix materials, with an extremely robust and fluid brass swivel. The chuck quickly “flips” for Presta or Schrader valves and threads on for superior engagement. An integrated Presta valve-core wrench completes the system, providing easy valve core tightening or removal for tubeless systems.

While "good enough" gets the job done, there is beauty in going above and beyond. The SILCA SuperPista Ultimate is the pinnacle of what a floor pump can achieve. From the highly accurate analog gauge to the magnetic HIRO dock to the lathe-turned Purpleheart wood handle, this floor pump embodies the SILCA mantra of passion, precision, performance. - Full Stainless Steel, Aluminum, Wood and Brass Construction—NO PLASTICS - SILCA Lifetime PLUS Shield Warranty—the most comprehensive warranty in all of Cycling - Ergonomic Purpleheart wood and Investment Cast Stainless Steel Handle - Full IGUS Linear Bearings for Ultimate Smoothness - Thick Full Grain Leather Piston Gasket—More Efficient and Durable than Rubber! - 1% Gauge Accuracy allows for Ultimate Ride Tuning

Compact and super efficient high pressure bicycle hand pump featuring a knurled barrel for superior grip while pumping. Its proven engineered design with an overlapping handle is constructed from machined aluminum, providing superior durability, minimal weight and all of the style. The integrated ABS Flex Hose is presta and shrader valve compatible, and greatly improves pumping action and ergonomics. This mini pump is completely rebuildable and made with the best materials available. With up to 120 PSI (8.3 BAR) of pumping power, the Grip Drive HP is excellent for all high-pressure bicycle tire applications. - 230 mm, 105g - 120 psi, 8.3 bar. - Grip Textured CNC machined aluminum construction with compact overlapping handle. - Presta and Schrader valve compatible ABS Flex Hose. - Includes Composite Matrix frame mount

This is a replacement hose for your Lezyne Micro Floor Digital Drive pump. It offers an integrated, highly advanced, inline digital gauge and ABS Flip-Thread chuck.

Pssstttt. Tired of hearing that when you disconnect your shock pump? Well, hear it no more thanks to Topeak's Pressure-Rite. It's a must have for suspension fanatics as its ingenious design prevents air loss when adjusting shock and fork pressure. It's also available in a Presta version, perfect for disc wheels.

The Prestaflator ECO is designed with a medium flow trigger valve providing a perfect balance for inflation and seating tubeless tires. The dial pressure gauge lets you follow your progress visually. Designed for Bicycle Mountain & Road tires with a wide range of pressure requirements. Auto-Select Head Presta / Schrader auto-select head engages with a simple flip of the lever. Quick lever release minimizes air loss at disconnect. Quality Prestaflator is engineered specifically for the needs of bicycles and bicyclists. Only top quality materials are used for it’s components. We start with a cast Alloy body and give it a Nickel plated finish. The hose is made of reinforced PVC. It’s more flexible than rubber hoses and is rated for 300 PSI of continuous use. Smooth alloy clamps on the hose are more comfortable for use. The pressure gauge has a durable steel case covered with a rubber shock housing and offers accuracy with +/- 2%. The dial has a bicycle-specific pressure range of 12 Bar/174 PSI. It’s high enough to inflate any daily-use tire, but not excessive so the gauge is easy to read. Prestaflator – The Original Beware of fakes and cheap imitations sold by one-product sellers. These are not real brands that can stand behind your product. Prestacycle is the originator of the Prestaflator. We are a full-line Bicycle tools company providing the Cycling industry globally with world-class tool designs. Our R&D has created a proven design that we have consistently improved-upon through years of experience. Prestaflator is different… a high quality, serviceable tool… designed, built and warranted for use on Bicycles. Specifications: - 2" / Steel body dial pressure gauge. - 150 PSI (in 2 PSI increments). - 10.5 Bar (in 0.2 Bar increments). - Copper coil mechanism provides good accuracy. - Polymer Presta / Schrader auto-select head. - Engages any valve with a simple flip of the lever. - Presta AND Schrader - Quick lever release minimizes loss at disconnect. - Replaceable I/M compressor quick-release attachment. - Rubber pressure gauge housing for shock protection. - Cast alloy pistol grip handle with Nickel-plated finish. - Thumb-control pressure release button. - High-pressure hose for easy access on any wheel. Disclaimers Air compressor and air hose with quick release connector required for use – not included. Maximum air pressure is limited by your compressor’s capabilities.

Easy to use, powerful, durable and economical, Park Tool's PFP-8 Home Mechanic's Floor Pump has a place in every garage and home bike shop and is perfect to take along to cycling events, too! It inflates like a champ thanks to its sturdy steel barrel, tough handle, composite thumblock head that fits Presta and Schrader valves, sturdy steel base, long hose and extra-large, easy-to-read gauge.

CO2 replacement cartridges Planet Bike's line of CO2 replacement cartridges make tire repairs quick and easy. - Our CO2 cartridges work in Planet Bike inflators as well as most competitors' inflators - Planet Bike cartridges are tested to the highest standards for durability, safety and reliability. They contain pure CO2 with no oils or contaminants - 100% recyclable steel cartridges - All threaded cartridges are compatible with Air Kiss, Red Zeppelin, Red Zeppelin 2 & Air Smith CO2 - Unable to ship to Canada

Lezyne's easy-to-use Alloy Drive CO2 is super-compact and portable. Its simple twist operation lets you control exactly how much CO2 you're putting into your tires. Plus, its aluminum construction is lightweight, durable and easy on the eyes. What's more, the Alloy Drive is Presta/Schrader compatible, comes with an anti-freeze sleeve, and works with all threaded cartridges. - CNC-machined aluminum dispenser with brass internals - CNC control knob twists for easy and controlled inflation - Twin Slip Chuck head presses on to Presta and Schrader valves - Neoprene sleeve insulates hand from cold during discharge - Compatible with threaded CO2 cartridges (sold separately)

Small, efficient, reliable—the three key features of the Air Tool MTB Mini pump. With the inverted dual chamber design, this pump moves 20% more air per stroke than the unit it replaced, yet is 10% smaller. - Inverted dual chamber design is smaller yet moves 20% more air per stroke when compared to our previous design, reducing pumping time by up to two minutes. - Twist locking head is easily converted to fit Presta or Schrader valves. - Machined outer barrel for extra grip while pumping. - Aluminum inner and outer chamber for durable performance. - Water bottle boss frame mounting bracket included. - Max pressure: 60 PSI (4.1bar) - Volume-per-stroke: 55cc - Water bottle boss frame mounting bracket included.

Will fit Specialized Sport/Comp/HP floor pumps from 2010 - present.

CNC machined aluminum dispenser with brass internals. Trigger Valve Operation for easy and controlled inflation. Twin Chuck head threads on to Presta and Schrader valves. Neoprene sleeve insulates hand from cold during discharge. Compatible with threaded CO2 cartridges. Includes one 16g cartridge. - Weight: 26g - Aluminum, a strong, lightweight, and durable material, is used to make various precision CO2 inflator components - CNC machined aluminum parts for precise and durable construction - Press on/off valve operation functions like a trigger, providing easy and precise inflation - Lezyne's ABS Flex Hose threads directly onto the valve for a secure, airtight connection. Compatible with Presta, and Schrader valves

Topeak's Joe Blow Sprint quickly inflates tires thanks to its durable aluminum barrel, a sturdy steel base, a tight-sealing aluminum thumblock head that fits Presta and Schrader valves and an oversized, padded handle. And, the easy-to-read, top-mounted gauge lets you dial in the perfect pressure every time!

Topeak's Pocket Rocket DX II boasts an aluminum construction for superb function, durability and max pump power. And, its aluminum thumb-lock head fits both Presta and Schrader valves.

The Mountain TT G Twin Turbo pump has a large, integrated 1-1/8"-diameter easy-to-read analog gauge. It fills both large-volume fat bike tires and higher pressure MTB tires with ease. TwinTurbo technology uses both strokes to compress air to deliver high-pressure output and saves time and effort. Integrated dust cap keeps pump head clean and thumb-lock lever ensures an air-tight seal. - Head: Presta / Schrader / Dunlop with integrated dust cap - Barrel: Aluminum - Thumb Lock/Handle: Polymer - Capacity: 60psi / 4bar, 1-1/8” Analog - Volume Per Stroke: 91cc - Added Features: Side mount bracket - Size: 25.3 x 4.9 x 4cm / 10” x 1.9” x 1.6” - Weight: 227g / 8oz

The world’s first CO2 inflator with tire gauge provides tire-inflation and tire-pressure measurement. The angled head fits Presta and Schrader valves and a special feature allows the user to adjust the flow while filling the tire. Dual-end design allows for one-cartridge storage. - CO2 inflator that features a gauge as well - Flow is adjustable using special feature - Compatible with both Presta and Schrader valves - Presta/Schrader with integrated dust cap, Push to inflate - Gauge: Reads 160 psi / 11 bar, 1-1/2” analog - Engineering-grade polymer - Weight: 45g /1.59 oz - Size: 6.5 x 5.2 x 3.3 cm / 2.5” x 2” x 1.3” - Accepts threaded cartridges - CO2 cartridges sold separately

Topeak's Mini Dual DXG is constructed of lightweight aluminum and sports a grippy Kraton and plastic handle for easy pumping. Topeak's thumb-lock SmartHead ensures an airtight seal on both Presta and Schrader valves and the built-in gauge lets you top off your tires with precision.

90 Degree twist style mini CO2 head used on SWAT products - Twist design allow CO2 cartridge to be threaded into head and then unthreaded to start CO2 flow. - Flow can be controlled or stopped by threading cartridge back into head. - Includes plastic spacer that allows head to be mounted for storage on cartridge without piercing it.

Get the convenience of CO2 inflation in a super-small pump that can be carried anywhere with Specialized's Cpr02 Pump. This little inflator boasts speedy, controlled inflation with the power of compressed CO2 and uses threaded cartridges

You'll have a whole lotta love for Planet Bike's Red Zeppelin CO2 Inflator Head on long rides. It fits Presta and Schrader valves and weighs next to nothing. Its small size means the Red Zeppelin fits easily in bags, pockets, and packs. And, it's compatible with threaded cartridges (sold separately). Now you'll never be stuck like a "Fool in the Rain."

Lezyne's Digital Check Drive is an innovative, compact digital pressure gauge. Composite matrix construction with integrated, low-profile Digital Strip Gauge. Machined aluminum head with flip-style Presta or Schrader valve compatible chuck. Super portable, highly accurate system. - Max: 350 psi/24 bar

With a conjoined secondary chamber that can be manually pressurized, Lezyne's Digital Pressure Over Drive floor pump is capable of conveniently seating tubeless tire systems. An integrated foot-lever opens and closes the chamber; when the chamber is full (Max. 220psi / 15 bar), flipping the lever down creates a powerful, continued blast of air that can seat road, mountain and plus-sized tubeless setups. This provides tubeless users an effective alternative to air compressors and CO2 units. Furthermore, a highly accurate digital gauge is incorporated into the pump for precision inflation when filling low- or high-pressure tires. Constructed from high-grade steel and aluminum, the Digital Pressure Over Drive is extremely durable and features an extra-long, nylon-reinforced braided hose. The innovative ABS2 chuck is both Presta- and Schrader-compatible and the system can also be used as a regular floor pump.

-High Volume Telescoping alloy barrels with high-pressure and high volume modes -Autohead fits Presta or Schrader valves without converting -Ergonomic T-handle for maximum pumping efficiency -Ultra compact design fits into many seat packs or jersey pockets -Includes mounting bracket -Rebuildable

The CNC Digital Drive is the ultimate, professional-grade bicycle floor pump which features a large digital gauge. Its full CNC-machined aluminum construction and hardware are built to last a lifetime, and replacement wear parts are readily available. Highly accurate, easy-to-read 3.5” (88.9 MM) digital gauge. The CNC Digital Drive comes with an extra-long, nylon-reinforced braided hose with aluminum couplers. At the end of the hose is the top-of-the-line ABS1 Pro floor pump chuck. - CNC-machined aluminum construction - Precision 3.5-inch digital gauge (220 psi / 15 bar) - Extra-long nylon reinforced braided hose with aluminum couplers - ABS1 Pro for Presta and Schrader chuck

Topeak's Micro Rocket AL is a small pump that packs a punch. Small in stature, this 6.3-inch pump is a giant in tire inflation. It utilizes a compact, single-action design to blast tires up to 160 psi.

The Kenai Outdoors Blast 2x pump offers the features and ease of use of a floor pump in a compact, easy to carry package. With folding foot pegs and t-handle, telescoping high volume barrel and flexible hose, the Blast 2x makes filling tires while on the road or trail easy. - Steel barrel with plastic fold out legs for stability - Shrader/Presta valve pump head - Includes bottle cage mount bracket - 10" hose

Have an old pump lying around that doesn't work with the standard Presta valves? This is your solution! Built to convert your old schrader pump into a Presta pump!

An easy-to-read top-mounted digital gauge with rubber bumper impact protection delivers accurate tire pressure readings up to 200psi / 14bar. The large padded handle provides comfort while the wide steel base keeps everything stable. The extra-long hose can even reach bikes mounted in a work stand. The SmartHead DX3 automatically adjusts to fit Presta or Schrader valves and a new lower-profile air-release button allows fine tuning of tire pressure while preventing unintended pressure release. - Head: SmartHead DX3 w/ air release button & extra-long hose - Barrel: Painted steel - Gauge: 200 psi / 14 bar, Top mounted digital (Tolerance : < 100 psi ± 1 psi / > 100 psi ± 1%) - Unit: psi, bar, kg / cm² - Battery: CR2032 x 1 (included) - Volume Per Stroke: 337cc - Handle: Oversize padded / Dual density polymer - Base: Hardened steel - Cushioned rubber for digital gauge protection, auto off, Dunlop valve adapter, Presta valve adapter, Ball / bladder heads, Hose dock - Size: 73.5 x 25.5 x 16.4cm / 28.9" x 10" x 6.5" - Weight: 1.97kg / 4.34lb

Planet Bike's amazing Air Smith combination CO2 inflator and pump has what it takes. The CO2 delivers a quick shot of air that won't leave you cryin', and the pump is great for topping off air pressures—or as a last resort when you're out there livin' on the edge. Worried that the C02 is difficult to use? Dream on! The Air Smith features a Smooth Regulator valve for precise and controlled inflation. And, the Air Smith inflates Presta and Schrader valves without adapters so you won't miss a thing. With an included 16g threaded cartridge and insulator, the Air Smith C02 can quickly get you back in the saddle again for some sweeeeeeeet emoooooooooooootion!

Angled Presta valve adapter - Designed for disc wheel use

Airflex Explorer Mini Pump is a small pump with great impact. The hose, stored in the pump tube, screws onto the valve head. Flexible hose prevents damage to valve stem during inflation. Pump handle is soft, easy-to-grip compound. Great pump for MTB or urban bikes. Small enough to fit in jersey pocket, but also includes a frame mount. - Inflates to 5 bar/73 psi - Compatible with Presta, Schrader, and Dunlop Valves - Includes a holder which attaches at cage mount - Length: 205mm - Weight: 132 grams - Made in Germany

Topeak's Presta Valve Extender is the perfect solution for getting to those hard-to-reach valve stems. It's precision-machined from aluminum and is designed to fit deep-dish carbon and aluminum rims that have a depth of 60 to 90mm. And, it comes with an O-ring seal to ensure a leak-free fit.

Bringing Lezyne's Smart Kit along means not letting a flat ruin your ride. It contains six glueless patches, a tire boot and a stainless-steel tube scuffer. All of this is stored in a compact pouch that fits just about anywhere for the ultimate in portability.

Floor pump efficiency in a super compact, hand pump size. Lightweight CNC machined aluminum barrel, piston, base, and T-handle optimized for high volume applications. Long, versatile hose improves pumping convenience. Stainless steel foot peg stabilizes pump during use. HVG version features integrated pressure gauge. ABS Flip-Thread Chuck equipped. Presta and Schrader compatible. Includes composite matrix frame mount. - Max: 90psi | 6.2bar - Size: 300mm | 225g

Lezyne's Sport Digital Drive Pump is built to last with steel barrel and piston with a molded composite matrix base. It's extremely accurate digital gauge and extra-long, high-strength hose with composite matrix couplers deliver high function and durability. Tough, painted finish with varnished wood handle. - ABS2 equipped

Easily adapts schrader only air compressors, floor pumps, and mini pumps to work with presta valves

RockShox simplifies your pack with this HP 2-Stage Air Pump. Throw it in your pack for every ride and you have both a shock and tire pump that boasts a 300psi capacity. The aluminum construction makes it super durable and the head fits both presta and Schrader valves. A large removable gauge is easy to read and the air-release button makes fine tuning pressure in shocks and tires a breeze. And it includes a mounting clip to mount to water bottle bosses.

The Airchecker from SKS is a fast and easy way to check your tire pressure. The swiveling head makes it a snap to reach your presta or schrader valve stem at any angle, and the backlit display with extra-large LED digits is always easy to read. This gauge measures up to 144 psi and reads in 10ths of psi.

Built and designed for bicycles, the INF-2 utilizes a redesigned, more durable, dual-sided, 360º rotatable Presta and Schrader head. The INF-2 also sports a new, lighter weight body and a redesigned trigger to facilitate multiple hanging options. It features a built in pressure gauge (0–160 psi, 0–11 bars) with a protective gauge boot, and the body accepts any 3/8" NPT male threaded fitting. Built for everyday shop use and 100% rebuildable!

Lezyne's Micro Floor Drive HV is a powerful mini-pump that thinks it's a floor pump. Its fold-out foot peg, high-volume barrel and aluminum construction make it easier than ever to pump up to maximum pressure of 90psi and get back on the trails. You'll also appreciate the ergonomic handle, extra-long hose and Presta/Schrader-valve compatibility.

Portland Design Works' Shiny Object is made from aluminum for strength and low weight so you won't think twice about bringing this ride essential along with you. A control knob keeps you in charge of the pressure, it takes threaded Co2 cartridges (sold separately) and it fits both Presta and Schrader valves. - Inflator only height: 44 mm (1.75") - Inflator only weight: 40 g (1.5 oz) 

Lezyne's Micro Floor Drive HP is a powerful mini-pump that thinks it's a floor pump. Its fold-out foot peg and aluminum construction make it easier than ever to pump up to a maximum pressure of 160 psi. You'll appreciate the ergonomic handle, extra-long hose and Presta/Schrader-valve compatibility. A frame mount and Speed Chuck is included, too.

Lightweight plugs for tubeless tire punctures. When paired with Genuine Innovations' Tubeless Tackle Kit (#G20439) or Tubeless Repair Kit (#G2650), you can plug pesky punctures in seconds and cycle confident for many rides to come.

If you're rolling on fat tires, the Fat Max 15 is for you. Most tire gauges just don't offer the precision needed for fat tires where 1 or 2 psi can make a huge difference. The strong and durable Fat Max 15 is specifically designed to read tire pressures from 2-15 psi so you can take the guess work out of finding the right pressure for your fat tire bike. - Designed with a low pressure range of 2-15 psi specific for fat bike tires - Durable case and crystal lens - Retains reading until reset - White face plate for easier reading - Compatible with Presta valves with removable core - Presta/Schrader adaptable head - Length: 120mm - Weight: 101 grams

Sunlite's Air Surge Frame Pump uses an oversized aluminum barrel to get your tires up to 100 psi quickly. The T-handle is comfy and makes airing up a new tube quick. And, the dual head works on both Presta and Schrader valves. A frame mount is included, too.

- High-flow steel barrel - 160 PSI high-pressure pump - Sturdy base, ergonomic T handle, long hose - Thumblock head for Schrader valves with Presta-valve adapter

• High-flow steel barrel • 160 PSI high pressure pump • Sturdy base and Ergonomic T- handle • Schrader valve w/ thumblock & presta adapter • EZ Read gauge

Sunlite's Air Surge Frame Pump w/Gauge uses an oversized aluminum barrel to get your tires up to 120 psi quickly. And you'll know your pressure thanks to the built-in gauge. The T-handle is comfy and makes airing up a new tube quick. And, the dual head works on both Presta and Schrader valves. A frame mount is included, too.

- Telescoping hand pump with integrated 30mm, 160psi gauge - Smart head is compatible with Schrader and Presta valves - Plastic handle unfolds into a T-handle for ease of use while pumping - Bracket included

- Mini multisport pump perfect for taking along on the next adventure - Ball needle and inflator included - Presta/Schrader reversible head - 2-way pumping action - Twist lock valve connection - 80 psi max - Head Type: PV/SV

20 grams of Genuine Inovations' exclusive size CO2 cartridge. Specifically designed for your larger volume 29ers, mountain and fat bike tires. These non-threaded CO2 cartridges work great with the Ultraflate (#G20310) and Full Metal Jacket (#G20440) inflators. Available in a 2-pack or 6-pack!

The Airlift 200 is a single action bike pump that is compact enough to keep on hand anytime and anywhere. It has a large chamber to fill tires fast and a pump handle that locks in place for extra security. - Smart head fits on both Presta and Schrader valves - Compact, 5-inch hose extends for easier operation - Pump handle locks into place - Includes a frame mount and two 4mm bolts - Pumps up to 80 psi maximum pressure