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, ensure 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. 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. This refill adapter is compatible only with Soda Terra Duo or Art Soda Maker CO2 cylinders in pink color. The adapter is not compatible with RPV valves (residual pressure valves). However, some RPV valves can be removed using a hex keyplease verify before ordering. The refill adapter is constructed from aluminum alloy and stainless steel, offering corrosion resistance, oxidation resistance, and long-term durability. It is designed to withstand high pressure, enabling convenient CO2 refills at home or during events. This soda filling adapter is intended for use with 60L pink CO2 bottles only. The CGA320 model is compatible with US and Canada standards and is not compatible with EU standard W21.8, such as in the UK and other countries. How to use: (1) Loosen the vent screw and use a wrench to attach the fill fitting to your CGA320 large CO2 tank. (2) Close the release valve by inserting the baking soda canister into the hole in the adapter. (3) Secure the cylinder in place, then slowly open the large carbon dioxide tank to fill the soda cylinder with CO2 gas. Wait approximately 2035 seconds until no gas flow is audible, then close the valve on the large CO2 tank. (4) Open the release valve to release any residual gas. Remove the soda cylinder to complete the process. Color: As shown Material: Metal Package Contents: 1 x CO2 Refill Adapter Note: Light reflection and differences in display screens may cause slight variations between the color of the item in the image and the actual product. Measurement may vary by +/- 1-3 cm.