MSW 38g CO2 Cartridge Bringing along a bulky air pump on your rides is a thing of the past. With the MSW CO2-38 gram cartridges you can inflate a tire in a fraction of the time it takes to pump up a tire with a hand pump and are small and compact making them convenient to carry. The 38-gram cartridges are compatible with all MSW CO2 inflators as well as other brand inflators. A single cartridge can fill a 26"or 27. 5" X 2. 0"-2. 5" tire to 45-60 psi or a 29" X 2. 0-2. 5" tire to 35-50 psi. Features3/8" x 24 TPI threading Compatible with all inflators One 38g cartridge will fill a 26"or 27. 5" X 2. 0"-2. 5" tire to 45-60 psi | Msw | Co2-38 Co2 Cartridge: 38G, Each 38G, Each