1.Made of high quality PA+PE, Composite Polyethylene Material with High Polymerization Nylon Fabric, More environmentally friendly and clean, without harming clothes. 2.Double Seal Zipper 3.Asymmetric design creates a secure seal and make a better protection of the Achilles heel. 4.Triple-Seal Turbo Valve 5.Anti-reflux groove with upgraded gasket make a great performance in seal. There is also a cap each valve to impact the gasket. 6.Our products manufactured under the strictest quality control standards and using the safest material, and don’t worry about the long-term effects of storage in the compression bags. 7.35*40cm,40*50cm,40*60cm,50*70cm,Can choose the right size,the set is 4 vacuum bags