Conforming to the contours and edges of your pond, the highly-flexible PolyGuard 20- by 20-Foot 20-Mil PVC Pond Liner retains water in your pond regardless of shape or size.With a flexible design that molds to the corners, contours, and shelving of backyard ponds, waterfalls, and water gardens, the liner ensures your entire pond is sealed and holds water year-round. Ready for any season, the durable mat is engineered to withstand extreme hot and cold temperatures, remaining flexible in the heat of summer or the freezing cold of winter. The liner easily attaches to any system, affixing to waterfall boxes, weirs, and skimmers. Safe for use, the pond liner does not harm fish, plants, or animals to keep your environment looking beautiful.Disclaimer: Plasticizers in the lining break down in direct sunlight. Cover the tarp with rocks, gravel, or sand to protect the liner from direct sun exposure.Keeping your pond looking great in every season, the 20- by 20-Foot PVC Pond Liner from PolyGuard helps you engineer amazing water features that are sure to impress friends and neighbors alike.