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.This adapter is not suitable for old cylinders (with pin type cylinder valves)1 x CO2 Cylinder Refill Adapter 1 x Hex Wrench 6 x Big Washer 9 x Small Washer 1 x Plug 1 x Instruction