Please check your tank thread before making an order. OD: 22mm W21.8-14 / DIN477 / M22-14 of 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 convenient refilling. 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 during this step, as pressing the adjusting rod 6mm will close the valve and prevent CO2 from entering.) 4. Connect the quick connector. 5. For most large cylinders: upright or lay the cylinder horizontally (some host tanks do not have a dip/syphon tube inside). 6. Carefully open the valve of the gas bottle. (Opening the valve too much or too quickly may cause the flow to stop. Open slowly until you hear airflow.) 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 residual gas. 10. Unscrew the CO2 adapter — filling complete. Color: Black Material: Metal Package Contents: 1 x Charging Valve Connector Only the above package content is included; other products are not included. Note: Light reflection and different display settings may cause slight color variations between the image and the actual item. Measurement error allowance is +/- 1–3 cm.