1. Wide Compatibility: It is suitable for many common carbon dioxide cylinders with traditional trapezoidal thread TR21 - 4. After installation, it can also be used with earlier versions of carbon dioxide carbonators and is compatible with Soda Aerators DUO, Art, and Terra. 2. Materials: This carbon dioxide adapter is made of brass and aluminum alloy, presenting a bright pink color. It has a tight seal, is environmentally friendly, durable, safe, and rust - resistant. 3. Easy Installation: Press the pen - like object and pull to remove the lower pink part from the bottom of the soda machine. For DUO and ART carbonators, a small piece may need to be cut on the cylinder housing to insert the cylinder. 4. Cost - saving: By using this quick adapter, one can use their own carbon dioxide cylinder with the new water carbonator. When refilling it oneself, the cost of replacing carbon dioxide cylinders can be saved. 5. Color: Red 6. Material: Copper + Aluminum 7. Package Contents: - 1 quick adapter - 2 rubber bands Only the above package contents are included. 8. Precautions: Light reflection and different displays may cause slight differences between the color of the items in the picture and the actual object. The measurement error may be +/- 1 - 3 cm.