Material Construction: Composed of 11 layers of composite film (including PET, PA, Aluminum, and PE) with a thickness of approximately 120140 m. Valve Type: Equipped with a PP (polypropylene) stopcock valve (as indicated by the "S" in NDEV21S), which typically includes a silicone septum for syringe sampling. Low Background: Uses environmental-friendly adhesives to minimize solvent residue (benzene, acetone, esters), resulting in 95% less organic solvent remnant than standard foil bags. Sample Stability: Provides up to five days of stability for most samples with minimal absorption. Temperature Range: Suitable for use in temperatures from -15C to +60C.