Please check your tank thread before ordering. OD: 22mm W21.8-14 / DIN477 / M22-14 on your CO2 tank. Common 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 tanks, allowing easy 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 (must turn the knob on the top of the black adapter to the highest position. The entire process does not require turning the adapter knob down to open the cylinder. If the adjusting rod presses down 6mm on the valve pin, this will close the valve and prevent CO2 from entering). 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 closes the flow if opened too much. This occurs if the large cylinder is opened too much or too quickly. The key is to open the large cylinder very slowly. You will hear the airflow. This allows 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 – done. 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 displays may cause the color of the item in the picture to appear slightly different from the actual product. Measurement may vary by +/- 1–3 cm. When shopping, please pay attention to the size and dimensions of the product to ensure it meets your needs. The title and description provide detailed information about the product, including features and specifications. We want you to be completely satisfied with your purchase. If you have any questions or concerns, please feel free to . We are here to help and will do our best to assist you. Thank you for choosing our product. We hope you enjoy it!