A super small (28mm x 27mm x 14mm) and light (12g) CO2 head \n - Head is threaded so no air is lost when connected to valves \n - Air flow is controlled by the CO2 cartridge. Simply thread on the cartridge to head and control air flow by unthreading the cartridge slowly. Cartridge can be tightened again to save leftover CO2 \n - Includes foam sleeve for CO2 cartridges