Item specifics: Material: Aluminum alloy, Copper Color: gold; purple silver Thread: TR21-4 Function: Connect the soda cylinder with TR21-4 thread to the DUO, TERRA soda machine with quick connect cylinder Features: 1 Fits many standard CO2 cylinders that have the conventional trapezoidal thread TR21-4, bottles with up to 60 liters and 425 g CO2. Made of robust and extra light aluminum. environmentally friendly, robust, high security, rustproof and durable. 1. Remove the pink piece from the bottom of the Terra Water Sprinkler by pressing the pins shown in the included instructions and pulling the unit downwards. compatible DUO and ART bubbles must have a small piece of the housing cut out in the cylinder compartment so that the cylinder can be inserted into the compartment. 2. Screw our quick adapter with the inserted flat seal firmly onto the conventional TR21-4 valve. Fits perfectly on our 425g CO2 cylinders but of course also on other manufacturers' cylinders such as Crystal 2.0, Penguin, Cool and Aqvia. IMPORTANT: If the adapter cannot be screwed into the CO2 bottle's HANDLE, this cylinder is not compatible with this adapter. If you have any questions, we will be happy to answer them. 3. Insert the 425g cylinder into your Soda DUO, Art or Terra and fix it as usual by pulling down the quick release device and pushing it into the water sprinkler until the device clicks into place. IMPORTANT: The hexagon screw (safety valve) on the TR21-4 valve must be positioned so that it looks OUT of the device and NOT sideways or into the storage unit. Why choose us? What if you only have a blue CO2 bottle but are too lazy to go out and refill? Or are there no gas stations nearby? The improved quick adapter from WADEO, specially developed compatible sparkling water heaters with pink CO2 bottles. If you only have the blue CO2 bottle, bring this adapter home, you can refill the blue bottle directly, then add the adapter, then you can use it on Terra/Duo/Art series Sodastream soda machines. Scope of delivery: 1 * Quick Adapter