Please check your tank thread before ordering. OD: 22mm W21.8-14 / DIN477 / M22-14 for your CO2 tank. Commonly used in Russia, Korea, Japan, UK, France, Switzerland, Sweden, Ukraine, Germany, South Africa, Czech Republic, Singapore, etc. This item is used to refill small Argon/CO2 tanks from larger CO2 cylinders, allowing easy refilling of small tanks. CO2 Refilling Station Charging Adapter Type: W21.8-14 How it works: 1. Cool the cylinder in the freezer for 1 hour. 2. Screw the CGA320/W21.8 connection to a commercial CO2 gas cylinder. 3. Disconnect the quick connector of the black adapter, then tighten the black adapter to the cylinder (ensure the knob on the 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 the 6mm wide valve pin, the valve will close and CO2 cannot enter). 4. Connect the quick connector. 5. For most large cylinders: stand the cylinder upright or lay it down (some host tanks do not have a dip/syphon tube inside). 6. Carefully open the valve of the gas bottle (the valve on the cylinder may close the flow if opened too much. This occurs when the main cylinder valve is opened too far or too quickly. Open the valve slowly and carefully. You will hear the airflow. This ensures successful filling). 7. After approximately 15–20 seconds, the cylinder is completely filled. 8. Close the valve of the gas bottle. 9. Open the bleed screw to release residual gas. 10. Unscrew the CO2 cylinder—refilling is complete. Color: Black Material: Metal Package Contents: 1 x Charging Valve Connector Note: Only the items listed above are included; other products are not included. Light reflection and different display settings may cause slight color variations between the product image and the actual item. Measurement error allowance: +/- 1–3 cm.