Features: Fits many common CO2 cylinders which have the conventional trapezoidal thread TR21-4, bottles with up to 60 liters and 425 g CO2. Made from robust and extra-light aluminum. Environmentally friendly, sturdy, high security, rustproof and durable. Remove the pink piece from the bottom of the Terra Sparkling Water Maker by pressing in the pins as shown provided and pulling the device downwards. With the DUO and ART bubblers, a small piece of the housing in the cylinder compartment must be cut out so that the cylinder can be inserted into the compartment. Screw our quick adapter with the inserted flat seal hand-tight onto the conventional TR21-4 valve. Fits perfectly on our 425g CO2 cylinders but of course also on cylinders from other manufacturers such as the Crystal 2.0, Penguin, Cool and Aqvia. IMP : If the adapter CANNOT be screwed onto the CO2 cylinder HAND-TIGHT, this cylinder is not compatible with this adapter. If you have any questions, we will be happy to answer them. Insert the 425 g cylinder into your , Art or Terra and fix it as usual by pulling the quick-release device down and pressing it into the sparkling water maker until the device snaps into place. IMPORTANT: The TR21-4 valve hex head screw (safety valve) must be positioned so that it faces OUT of the unit and NOT sideways or into the machine. Including two washers, one of which has been installed in the product Specifications: Color: Material: aluminum alloy, brass Thread: TR21-4 Function: Connect TR21-4 threaded cylinders to DUO and TERRA machines using quick-connect cylinders Package Included 1* Quick Connect Notes: 1.Due to the lighting effects and shooting angles, the color of the item and that shown in the picture might have a nuance. 2.Due to manual measurement, there might be a tolerance in the product size 【Eco-Friendly and Sustainable】Made with environmentally conscious practices, this product is eco-friendly and contributes to sustainability efforts. It is designed to minimize waste and reduce environmental impact. 【Exceptional Performance】Engineered for high efficiency and effectiveness, this product delivers outstanding results every time. Its advanced features ensure consistent performance, making it a reliable choice for your needs 【User-Friendly Design】Ergonomically designed for ease of use, this product offers intuitive controls and a comfortable grip, making it perfect for both beginners and experienced users. 【Versatile Functionality】This product is multifunctional and can be used for a variety of tasks, providing you with the flexibility and convenience needed to handle multiple uses with a single tool. 【High-Quality Materials】Crafted from premium, durable materials to ensure longevity and superior performance. Each product is meticulously tested to meet high standards of quality and safety.