The CO2 cylinder refill adapter comes with a 3500psi/2000psi pressure gauge that can monitor pressure changes in real time. Please select the appropriate pressure gauge . When using it, please that the pressure value does not exceed the pressure specification of the receiving tank. First, loosen the vent screw, then use a wrench to install the fill fitting onto the (CGA320) Large CO2 Tank, then rotate the empty cylinder to the fill position and tighten the vent valve to lock the cylinder securely in place. Finally, slowly open the large CO2 tank to fill. Refill Co2 only fits Soda Terra Duo or Art Soda Maker CO2 cylinder which is pink color. Our adapter does not work RPV valve (residual pressure valve), but some RPV valves can be removed by hex key, please check before ordering. The refill adapter is made of aluminum alloy and stainless steel, which is -resistant, oxidation-resistant and long-lasting, etc. It can withstand the pressure well, and you can inflate CO2 at any time at your home or party. Soda Filling Adapter for 60L pink CO2 bottles only. Model number CGA320 is for US/Canada only and does to EU standard W21.8 (e.g. UK and other countries). How to use? (1) Loosen the vent screw and use a wrench to install the fill fitting to your CGA320 large CO2 tank. (2) Close the release valve by pushing the baking soda canister into the hole in the adapter. (3) Lock the cylinder securely, then slowly open the large carbon dioxide canister and add carbon dioxide gas to the soda cylinder. Wait about 20-35 seconds until no gas flow can be heard to close the valve on the large carbon dioxide canister. (4) Open the release valve to release residual gas. Remove the soda cylinder to complete the installation. Colour:As Shown Material:Metal Package Contents: 1 * S Refill Adapter 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.