Please check your tank thread before ordering. OD: 22mm W21.8-14 / DIN477 / M22-14 compatible with CO2 tanks commonly used in Russia, Korea, Japan, UK, France, Switzerland, Sweden, Ukraine, Germany, South Africa, Czech Republic, Singapore, and other regions. This adapter is designed to refill small Argon or CO2 tanks from larger CO2 cylinders, allowing convenient and efficient tank refilling. CO2 Refilling Station Charging Adapter Type: W21.8-14 How it works: 1. Cool the cylinder in a freezer for 1 hour. 2. Attach the CGA320/W21.8 connection to a commercial CO2 gas cylinder. 3. Disconnect the quick connector of the black adapter, then securely tighten the black adapter onto the cylinder. Ensure the knob on top of the black adapter is in the highest position. Do not turn the adapter knob down to open the cylinder. If the adjusting rod presses down on the 6mm wide valve pin, the valve will close and prevent CO2 from entering. 4. Reconnect the quick connector. 5. For most large cylinders, either stand upright or lay the cylinder horizontally, depending on internal design (some tanks do not have a dip/syphon tube). 6. Carefully open the valve of the gas bottle. Opening the valve too wide or too quickly may cause the flow to shut off. Open slowly until gas flow is heard to ensure successful filling. 7. After approximately 15–20 seconds, the cylinder will be fully filled. 8. Close the valve of the gas bottle. 9. Open the bleed screw to release any residual gas. 10. Unscrew the CO2 adapter—refilling is complete. Color: Black Material: Metal Package Contents: 1 x Charging Valve Connector Note: Light reflection and differences in display settings may cause slight variations between the color of the item in images and the actual product. Measurement may vary by up to +/- 1–3 cm.