Material: Aluminum alloy, Copper Color: Gold; Lilac Silver Thread Type: TR21-4 Function: Connects CO2 cylinders with TR21-4 thread to DUO, TERRA, and ART soda machines with quick-connect cylinder systems Features: - Compatible with common CO2 cylinders featuring standard trapezoidal TR21-4 thread, supporting bottles up to 60 liters and 425g CO2 - Constructed from durable, lightweight aluminum alloy for long-lasting performance - Environmentally friendly, robust, safe, rust-resistant, and built to last - Fits 425g CO2 cylinders including those from various brands such as Crystal 2.0, Penguin, Cool, and Aqvia - Includes flat seal for secure connection Usage Instructions: 1. To install on Terra Water Sprinkler, remove the pink piece from the bottom by pressing the pins as shown in the instructions and pulling the device downward. For compatibility with DUO and ART models, minor modification may be required in the cylinder compartment to allow proper insertion. 2. Screw the quick adapter firmly onto the TR21-4 valve using the included flat seal. Ensure a tight fit. Note: If the adapter does not screw into the CO2 cylinder valve, the cylinder is not compatible. 3. Insert the 425g CO2 cylinder into your Soda DUO, Art, or Terra machine. Secure it by pulling down the quick-release lever and pressing the cylinder into place until it clicks. Important: Position the hexagonal safety valve (TR21-4) so it faces outward, not sideways or inward toward the housing. Why Choose This Adapter? Ideal for users who want to reuse existing 425g blue CO2 cylinders with compatible Sodastream series machines. Enables direct refilling of compatible cylinders and easy integration with Terra, Duo, and Art models using the adapter. Package Includes: 1 x Quick Adapter