Material: Aluminum alloy, Copper. Color Options: Gold, Lilac Silver. Model: TR21-4. Function: Connects a soda cylinder with TR21-4 thread to a DUO, TERRA, or ART soda machine with a quick connection cylinder. Fits many common CO2 cylinders with the conventional trapezoidal thread TR21-4, including bottles up to 60 litre and 425g CO2. Condition: New. Origin: China. To install on a Terra machine, remove the pink piece from the bottom of the Water Sprinkler by pressing the pins as shown in the supplied instructions and pulling the device out downwards. For compatibility with DUO and ART machines, a small piece of the housing must be cut out in the cylinder compartment so that the cylinder can be inserted. Screw the quick adapter with the inserted flat seal firmly onto the conventional TR21-4 valve. Fits perfectly on 425g CO2 cylinders and is also compatible with cylinders from other manufacturers such as Crystal, Penguin, Cool and Aqvia. Insert the 425g cylinder into your Soda DUO, Art or Terra and fix it as usual by pulling down the quick release device and pressing into the water spreader until the device clicks into place. Important of the TR21-4 valve must be positioned so that it faces OUT of the device. If the adapter cannot be screwed into the CO2 bottle handle, the cylinder is not compatible with this adapter. Package Includes: One Quick Adapter.