Feature 1SUITABLE MODELS: Male thread soda water CO2 adapter connector is applicable for DUO, for TERRA, for Art soda water machines. 2THREAD AND OPERATION: The thread of our CO2 adapter is TR21 4 male thread can be inserted after removing the base of 60L CO2 cylinder, there are different operation methods according to different cylinders, easy to install. 3POLISHED SURFACE AND GOOD SEALING: Soda water CO2 adapter is with well polished surface and with good sealing so the CO2 will not be leaking. 4EASY TO CARRY: The overall weight of this soda machine CO2 connector is light and very easy to carry, you can take the connector with you at all times. 5MADE OF BRASS AND ALUMINUM ALLOY: Soda water CO2 adapter is made of brass and aluminum alloy, resistant to corrosion, durable and safe.Item Type: CO2 AdapterMaterial: Brass, Aluminum AlloyThread: TR21 4 ThreadFunction: Connects TR21 4 thread soda cylinders to for DUO, for TERRA, for Art soda machines that use gas cylinders. With this adapter you can continue using traditional screw valve CO2 cylinders. The adapter can be used with 60L aluminum CO2 cylinders with screw valves. Package List: 1 x Connector2 x WasherNoteWhen connecting TR21 4 threaded soda bottle with joint, if it is found that the gas bottle cannot be put into the machine, it is necessary to remove the baffle at the bottom of the machine, so that the joint and the gas bottle can be put into the machine together.