Use For Terra DUO Quick Connect Machines. With Quick Disconnect Connector/2000PSI Gauge/Bleed Valve. Hose Lenght 50Inch(125cm) Or 100Inch(250cm), Soft and Durable. This Item Use For Terra DUO To External Tank Cyclinder Connect.Like 5lb, 20LB or 50lb commercial CO2 tanks. Allows External Tank Cyclinder Valve Connector Thread W21.8-14. W21.8-14(DIN 477) connector Compatible With M22-14, Common in , JP, UK, , , , , Switzerland, Russia, Ukraine, South Africa, Sweden, Chile, , Singapore. This item works with CO2 only, not liquid CO2.It can't use siphon tube Co2 Tanks 't disconnect the quick disconnect under pressure, it will be blowed out the o ring in quick disconnect(female QD),suggest drain residual pressure on Machines. How it works: Screw the Nut to CO2 cylinder and tighten it by wrench. CQC adaptor connect the quick coupler. CQC adaptor connect into machine. Open the valve of the . Done,you can use your machine. if you to unscrew the item from the machine: valve of the . Press button of machine to drain residual Co2(if you 't this guide to disconnect the coupler, the o ring of quick coupler will be blowed out) Unscrew CQC adaptor from machin and unscrew Nut from CO2 cylinder Model Number: Terra DUO Type: Air Gauge: 2000Psi color:As shown :Plastic + Metal Package Contents: 1 x Co2 Tank Adapter Hose Kit Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the a little different from the real thing. The measurement allowed error is +/- 1-3cm.