This is a premium brass adapter for soda water with good durability. This easy-to-use soda bottle refill adapter allows you to refill your own CO2 from a larger bulk bottle to a smaller soda bottle. Easy to install and use. You can try it. Features: This easy-to-use soda bottle refill adapter allows you to refill your own CO2 from a larger bulk bottle to a smaller soda bottle. Made of high-quality brass with good durability. Suitable for W21.8-14 soda bottle refill adapter relief valve or CGA320 connector. Can be used with large CO2 tanks with CGA320 connectors. Easy to install and easy to use. How to use: Screw the adapter onto a commercially available CO2 cylinder. The air carbon dioxide cylinder is screwed into the adapter. Open the valve on the large bottle. After about 15 or 20 seconds, the cylinder is completely full. Close the valve on the large bottle. Open the exhaust valve. Unscrew the CO2 bottle. Specifications: Name: Adapter Material: Brass thread for small bottle: 21*4 thread for large bottle: Thread type W21.8-14: Outlet valve diameter 22mm Product size: 45 * 40 * 30mm / 1.77 * 1.57 * 1.18in Product weight: 148g/5.21oz Package size: 100*60*30mm/3.94*2.36*1.18in Package weight: 150g / 5.29oz Packing list: 1 * Adapter