Material: Aluminum alloy, copper Color: Gold; lilac silver Thread type: TR21-4 Compatibility: Connects CO2 cylinders with TR21-4 thread to DUO, TERRA, and ART soda machines with quick connection system Features: - Fits common CO2 cylinders with standard trapezoidal TR21-4 thread, up to 60 liters and 425g CO2 - Constructed from durable, lightweight aluminum alloy - Environmentally friendly, robust, safe, stainless, and long-lasting - Includes flat seal for secure connection - Designed to fit 425g CO2 cylinders; compatible with various brands including Crystal 2.0, Penguin, Cool, and Aqvia Usage instructions: 1. For Terra models, remove the pink piece from the bottom of the water dispenser by pressing the pins as shown in the included instructions and pulling the unit downward. For DUO and ART models, modify the housing slightly in the cylinder compartment to allow proper insertion. 2. Screw the quick adapter firmly onto the TR21-4 valve of the CO2 cylinder using the included seal. Ensure a tight connection. Note: If the adapter does not screw into the 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 on the TR21-4 cylinder so it faces outward from the machine, not sideways or inward. Note: This adapter allows use of refillable CO2 cylinders with compatible soda makers. Ideal for users seeking convenience without frequent bottle replacements. Package includes: 1 x Quick Adapter