45-Mil EPDM Rubber Pond liner with UnderGuard Underlayment has a Limited Lifetime Warranty Durable, puncture resistant, extremely versatile for use in waterfall features, pond kits, water gardens, retention basins, koi ponds, aquaponics, lakes, stream liners, and fish hatcheries. Does not contain plasticizers, which become brittle and cause cracks or splits. Easy to install, lays flat, very pliable for easy shaping and feature fitments. Geotextile will come in multiple pieces equivalent to total square footage. Certified Fish & Wildlife Safe by Guardian Systems Inc