Clever design allows for one handed operation on both Presta and Schrader valve systems. The Air Chuck operation is dead simple. Just thread on your cartridge and slide mouth of inflator over valve. Push forward to compress the Air Chuck and release air from the cartridge. To regulate air flow, pull back on the Air Chuck head. It's that easy! The simplicity of a CO2 inflator like this trumps any mini-pump on the market. The ease of inflation, assurance that you are going to ride home on a properly inflated tire and small size is an absolute necessity. Steel and alloy construction means the Air Chuck Elite will stand up to abuse and the test of time. The kit includes the Air Chuck, one threaded 16 gram CO2 cartridge. and one 20g CO2 Cartridge.