Please check your tank thread before placing an order. OD: 22mm W21.8-14 / DIN477 / M22-14 for your CO2 tank. Compatible in: Russia, South 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 a larger CO2 cylinder, enabling convenient refills. CO2 Refilling Station Charging Adapter Type: W21.8-14 How it works: Follow these instructions carefully: 1. Cool the small cylinder in the freezer for 1 hour. 2. Screw the CGA320/W21.8-14 connection onto a commercial CO2 gas cylinder. 3. Disconnect the quick connector of the black adapter, then tighten the black adapter onto the small cylinder. Ensure the knob on top of the black adapter is fully turned up (do not turn it down — pressing the adjustment rod down 6mm will close the valve and prevent CO2 flow). 4. Reconnect the quick connector. 5. For most large cylinders: position the large cylinder upright or lay it on its side (note: some large cylinders do not have a dip/siphon tube). 6. Carefully open the valve of the large gas cylinder. Opening too wide or too quickly may restrict flow. Gently open until you hear steady airflow. 7. After approximately 15–20 seconds, the small cylinder is fully filled. 8. Close the valve on the large gas cylinder. 9. Open the bleed screw to release residual gas. 10. Unscrew the charging adapter. Color: Black Material: Metal Package Contents: 1 × Charging Valve Connector Note: The package includes only the charging valve connector; other items are not included. Light reflection and display differences may cause slight color variation between the image and the actual product. Measurement tolerance: ±1–3 cm.