Material: Aluminum alloy, Copper Color: Gold; Lilac Silver Topic: 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 content - Constructed from durable, lightweight aluminum alloy and copper components - Environmentally friendly, robust, safe, corrosion-resistant, and long-lasting - Designed to fit 425g CO2 cylinders, including those from various brands such as Crystal 2.0, Penguin, Cool, and Aqvia - Includes a flat seal for secure connection Usage Instructions: 1. To install on Terra, DUO, or ART models, remove the pink piece from the bottom of the water dispenser by pressing the pins as shown in the instructions and pulling the component downward. In some models, minor modification of the cylinder compartment housing may be required to allow proper insertion. 2. Screw the quick adapter firmly onto the TR21-4 valve of the CO2 cylinder using the included flat seal. Ensure the connection is tight and secure. Note: If the adapter does not screw into the valve, the cylinder is not compatible. 3. Insert the 425g CO2 cylinder into the soda machine and secure it by lowering the quick-release lever until it clicks into place. Ensure the hexagonal safety valve on the TR21-4 cylinder is positioned outward, not sideways or inward, for correct alignment. Why choose this adapter? Ideal for users who wish to continue using standard TR21-4 CO2 cylinders with compatible soda machines. Enables convenient use of refillable cylinders without the need for proprietary systems. Package Includes: 1 x Quick Adapter