Adapter for filling to fill the cylinder sodastream DUO,Terra,Art from a large tank co2 with W21.8-14 thread. High quality made of aluminium. li> Comes with a pressure gauge 250 bar. li> Connection W21.8-14RH. li> For filling sodastream DUO,Terra,Art cylinders. li> With relief valve. li> How do you use that? Before refilling, first cool the pink sodium stream bottle in the freezer for 1 or 2 hours and turn the large CO2 tank upside down if there is no immersion/syphon tube in the tank. 1. Prepare the necessary elements: key, set of adapters for filling, filling tank Co2, empty soda stream cylinder. 2. First release the vent valve, then use the wrench to install our filling station in a large Co2 tank (W21.8-14/CGA320). 3. Place the empty cylinder in the filling place with a rotating motion. 4. Tighten the vent valve tightly to lock the cylinder tightly. 5. Slowly open the large Co2 tank to replenish the gaz Co2 to the sodium stream cylinder. After about 1520 seconds, the cylinder is completely filled. 6. Filled to the full. First, close the large Co2 tank valve, then unscrew the relief valve to release the gaz and cylinder. Uninstall the sodastream-Ready cylinder. 7. Prepare soda water freely. Although please chill the pink sodastream cylinder in the freezer for 1-2 hours first and turn the large CO2 tank upside down, you can fill more gas, but this filling method does not have a gas booster to liquefy the gas, it is only a gas conversion between gas cylinders, so It cannot be filled with gas as much as the original pressure equipment.