Specification Brand : TizZo BulletPoint1 : BulletPoint2 : BulletPoint3 : BulletPoint4 : BulletPoint5 : Capacity : 600 milliliters Color : Silver ExternallyAssignedProductIdentifier1 : 0779675550799 ExternallyAssignedProductIdentifier2 : 779675550799 IncludedComponents : 4 Prem Vati ItemName : Gas Sampling Bags with Single/Double Valve, 30mL~500mL, PTFE Aluminum Foil Air Bag, Gas Collection and Storage Bag, Keep Gas Away from Light - 5Pcs (300ml, Single Valve) ItemPackageDimensions_Height : 254 millimeters ItemPackageDimensions_Length : 254 millimeters ItemPackageDimensions_Width : 254 millimeters ItemShape : Square ItemTypeKeyword : science-lab-sample-bags Manufacturer : TizZo Material : aluminum, PTFE,PET,PP ModelNumber : 5ml~500ml NumberOfItems : 5 NumberOfPieces : 4 PartNumber : TizZo-SamplingBag ProductDescription : Single Valve Bag It's a sampling bag with only one valve installed. Double Valve Bag It's a sampling bag with two identical valves installed on it. The inlet and outlet of the single valve sampling bag pass through one valve Differences One valve of the double valve sampling bag is inlet and the other is outlet. The advantages of the double valve bag are: several small capacity air bags can be connected in series to form a large gas sampling bag; and one in and one out is convenient for cleaning the gas sampling bag