Dura Skrim R20WW Liner 6' x 10' Polyethylene Film - White 20 mil For Aquaponics and Hydroponics Grow Beds, Modular Tanks, Landfill Covers, Remediation Liners and Covers Super durable; virgin outer layers of white high-strength polyethylene film laminated together with a black layer of molten polyethylene. Both outer layers contain UV inhibitors and thermal stabilizers to assure long outdoor life. All resins used in the food contact layer are FDA 21 CFR 177.1520 (c) 3.2 compliant. 5 year limited UV warranty. (Does not cover normal wear and tear or improper installation.)