They're incredibly simple, all of them act as a valve. Screw a CO2 canister on one end, screw the other onto your valve and either turn a knob or just press down and with a short blast of ...

12-GRAM CO2 POWERLETS - Compatible with most air rifles and air pistols SNUG FIT, SOLID SEAL - For reliable and consistent performance 5-COUNT BOX - Ideal for the air gun target sport enthusiast ...