Multi-layer foil gas sampling bags are ideal for sampling low molecular weight compounds such as carbon monoxide(CO),carbon dioxide(CO2) and permanent gases.They are also suitable for sampling sulfur compounds such as hydrogen sulfide(H2S),carbon disulfide(CS2) and mercaptans.It can be used to store general industrial gases for a long time,and to ensure concentration is not changing.Can be used under the temperature from -30℃ to +60 ℃. ● Material:Four-layer Aluminum Foil Composite Film ● Color:Silver ● 4-Layer foil:Polyurethane film(PET)+Nylon film (PA)+aluminum foil(AL)+polyethylene film(PE) ● Type:Single Rod valve ● Connected tube I.D.:6mm ● These flexible,sturdy bags are heat-sealed on all sides for resistance to chemicals and leakproof operation ● Low permeability and absorption ● Simple using,light-weight and easy to carry ● Chemically inert with moisture and light protection ● Can be used repeatedly,need to use clean air or high purity nitrogen purge