Please check your tank thread before making order.OD:22mm W21 8-14 / DIN477 / m22-14of your CO2 tank.common in:Russia , Korea Japan , UK , CLFrance , , , Switzerland ,Sweden , Ukraine , Germany .South AfricaCzech Republic , Singapore etc .This item is used to refill your small Argon / Co2 tanks from your tanks so that you can refill your small tanks easily .CO2 Refilling Station Charging Adapter Type:W21.8-14How it works: In order to use it correctly, please follow our instructions: 1. Cool for 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, and then tighten the black adapter to for the cylinder( must turn the knob on the top of the black adapter to the highest position,the whole process does not need to turn the adapter knob down to open for the cylinder,If the adjusting rod press down 6mm wide valve pin, this will close the valve and CO2 cannot enter) 4. Connect the quick connector 5.For most big cylinders: turn the big cylinder or lie it down.(somehost tank has not the dip/syphon tube inside.)6. Carefully Open the valve of the gas bottle(The valve on for the Cylinder closes the flow if it is opened to much.This will happen if you open the big cylinder too much / too fast.The trick is to open the big cylinder very carefully.You will hear the air flow.So to fill it successfull) 7.After about 15-20 sec.,The cylinder is completely filled 8. Close valve of the gas bottle 9. Opening the bleed screw to drain residual gas 10.Unscrew the CO2 - done Colour:Black Material:Metal Package Contents: 1 * Charging ValveConnector .