The CO2 inflatable joint is made of high-quality aluminum alloy and brass materials, safe and durable, wear-resistant and corrosion-resistant, ensuring long-term use. Fits only with quick connect CO2 cylinder systems with quick connect valve (no thread). It is specially designed for W21.8-14 valves of CO2 storage tanks. Compatible water carbonator models: Duo, Art, Terra. Our adapters come with a 3000psi gauge to let us know if the installation is under pressure. the safety of the inflation process. The built-in safety pressure valve is connected to the cylinder to prevent leakage. Using the adapter, you can fill your new Rapid Gas cylinders yourself. No tedious process, it will be the best extension of your terra/duo/art carbonated water dispenser. Instead of replacing empty CO2 cylinders, you can efficiently refill them , saving even more money. EASY TO USE: In just a few simple steps, connect the CO2 refill adapter to your pink CO2 cylinder and you can inflate it . Color: Silver & Gold Material: Aluminum brass Package Contents: 1 x CO2 Refill Adapter 3 x washer Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.