The CO2 transmission adapter is made of high-quality aluminum and stainless steel materials, safe and durable, wear-resistant and corrosion-resistant, ensuring long-term use.It is designed for W21.8-14 valves of CO2 tanks. Compatible with water carbonator models: Duo, Art, Terra.Our adapter comes with a 3000psi gauge which lets us know if the installation is under pressure. the safety of the inflation process. Built-in safety pressure valve connects to gas cylinders for no more leaks.Using the adapter, you can fill your new Rapid Gas cylinder yourself. No tedious process, it will be the best extension of your terra/duo/art water carbonator. Instead of replacing empty CO2 cylinders, you can efficiently refill them and save 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 .Colour:Rose Red & SilverMaterial:Aluminum+stainless steelPackage Contents:1 * CO2 Refill AdapterOnly 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.