Heavy duty cylinder connector. The product fills CO2 from large cylinders into smaller soda cylinders. Stainless steel filling adapter quick disconnector. Model Number:for W21.8 Work Pressure:310Bar Designed For Diving Cylinders . Instructions for use: Screw the adapter onto the larger CO2 cylinder. The empty soda cylinder is screwed into the fill adapter. Connect the quick plug. Open the valve of the larger cylinder. Wait for the cylinder to be fully filled, about . Close the valve of the larger cylinder. Open the bleeder valve of the filling adapter to remove residual gas. Screw off the carbon dioxide cylinder and complete the operation. Colour:silver Material:Metal Package Contents: 1 x Fill Station Adapter Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.