Topeak Air Booster CO2 Inflator Head with 16-Gram CO2 Cartridge (Steel, 1.7 x 1.4 x 0.6-Inch) Head fits Presda and Schrader valve types AirBooster features CNC aluminum construction ouble-ended design features CO2 cartridge engagement on one side, CO2 cartridge storage on the other 22.5-Gram/0.79-Ounce Accepts standard threaded CO2 cartridges