Features: Material: Material: Aluminum Alloy, Copper Color: Gold; Lilac Silver Theme: TR21-4 Function: Connects soda cylinders with TR21-4 thread to DUO, TERRA soda machines with quick connect cylinder Properties: 1 Fits many common CO2 cylinders with traditional trapezoidal thread TR21-4, bottle capacity up to 60 liters, CO2 capacity 425 grams. Made of strong and ultra-light aluminum. Environmentally friendly, strong, high safety, stainless steel and durable. 1. Press the pins as indicated in the included instructions, pull the device down and remove the pink part from the bottom of the Terra sprinkler. Compatible with DUO and ART bubblers, a small piece of the housing must be cut out in the cylinder compartment to insert the cylinder into the compartment. 2. Screw our quick adapter with the inserted flat seal securely onto the conventional TR21-4 valve. Perfect fit for our 425g CO2 cylinders, but also for cylinders from other manufacturers such as Crystal 2.0, Penguin, Cool and Aqvia. IMPORTANT: If you cannot screw the adapter into the CO2 cylinder handle, this cylinder is not compatible with this adapter. If you have any questions, we will be happy to answer them for you. 3. Insert the 425g cylinder into your Soda DUO, Art or Terra and secure it as usual by pulling down the quick release and pressing in the water diffuser until the unit clicks into place. IMPORTANT: The hexagon screw (safety valve) of the TR21-4 valve must be placed outside the device, not on the side or inside the storage unit. Why choose us? What if you only have a blue CO2 cylinder, but you are too lazy to go out to refill it? Or there is no refilling station nearby? WADEO's improved quick adapter has been specially developed for sparkling water heaters compatible with pink CO2 bottles. If you only have a blue CO2 bottle, take this adapter home and you can directly refill the blue bottle, then add the adapter and you can use it on your Terra/Duo/Art series Sodastream soda machine. Scope of delivery: 1 * Quick Adapter