VEVOR Pool Cover Water Bags, 12 Packs 8 Ft, Double Chamber Pool Cover Water Tubes, 0.4mm Thick PVC Bags Weights with Leakproof Screw Cap, for Inground Swimming-Pool Covers Winter Closing, BlueReliable Pool Cover ProtectionHeavy-Duty PVC ConstructionThoughtful Design DetailsLeak Prevention TipAll-Weather DurabilitySturdy Dual-Chamber StructureThickness: 0.02 inch / 0.40 mm,Welding Process: Edge High-Frequency Welding, 0.59 inch / 1.5 cm width,Item Model Number: SSPCWB-05,Set Includes: 12-Piece Set,Product Dimensions: 93.70 x 11.81 inch/2380×300mm,Chamber: Dual Chamber,Net Weight: 18.37 lbs / 8.33 kg