CO2 Tank 22mm to 21mm Adapter Converter - for standard cylinder hasn't pin connect to co2 Regulator with a free CO2 Regulator Solenoid O Ring 22mm co2 Regulator THREADS ~ British BS341 No. 8 /European DIN 477 No. 6 / SN 219505 Type 7 /French NF E 29-650 Type C / Australian AS2473 Type 30 / TAIWAN To 21mm CGA 320 co2 CYLINDER VALVE THREADS For American standard specifications type CGA 320 co2 cylinder "hasn't pin" attach to an Australian, Asian or European standard specifications co2 regulator.