Item Type: CO2 Cylinder Refill Adapter_x000D_ Material: Brass_x000D_ Connector: CGA320 to TR21 4 1[Suitable for Low Temperature] This adapter of ours can be used many times in freezing temperatures, making it more convenient for you to use. 2[Excellent Filter Element] Our adapters use an improved filter material that eliminates the taste and smell of carbonated water for a better experience. 3[Brass Material] Brass has high strength, good plasticity, can withstand cold and hot pressure well, and has a long service life. 4[Good Sealing Performance] There is no air leakage when using this adapter to connect the cylinder, and the use is more assured. 5[Wide Range of Application] The filling adapter can connect the cylinder to any large CO2 tank, suitable for large gas tanks with or without residual pressure valve.1 x CO2 Cylinder Refill Adapter 1 x Hex Wrench 6 x Big Washer 9 x Small Washer 1 x Plug 1 x Instruction This adapter is not suitable for old cylinders (with pin type cylinder valves)