Details: A with 2000psi pressure gauge for air release - W21.8 B with air release 2000psi pressure gauge - CGA320 C-band radial 3500psi pressure gauge with air release - W21.8 D-band radial 3500psi pressure gauge with air release - CGA320 1.Allows to use a standard CGA-320 large CO2 tank in most soda machines. Works with most soda Machines and allows normal operation without any permanent changes. 2.Save money on refills. This system allows you to connect your soda Machine to an external Non-Siphon CO2 Tank that has a CGA-320 Outlet Valve, like 5lb, 20LB or 50lb commercial CO2 tanks. 3.DN3 6mm Microbore Pant length 5ft(1.5 meters), high pressure pants .very soft,not easy to fold break. 4.Light weight only about 0.33kg.Compare to other heavy ones,it is easier to install. CGA320 Valve of CO2 Tank (USA, CAN, Brazil, Colombia, Philippines...) DIN477/W21.8-14/JIS m22-14 Valve of Co2 Tank (KOR,JP,UK,CI,FR,PL,NO,CH,RU,UA,GE,SE,South Africa,Czech Republic,Singapore...) Package Includes: 1 x Pant Adapter Kit to CGA320/W21.8 (with gauge as your choice) How to screw nut to CO2 gas tank: if you want to unscrew the pin valve from the machine: 1.Close valve of the large gas bottle 2.Press button more serval time to drain residual Co2(if you disconnect the coupler directly without this step,the o ring in quick coupler will be blown out) 3.Disconnect the quick coupler