VEVOR Pond Skins 20 ft. x 25 ft. Pond Liner 45 Mil Thickness Pliable EPDM Material for Fish/Koi Ponds Water Gardens, Black CTFSMHSEPDM20SZTDV0 - The Home Depot
MacCourt 4.5-ft L x 6.5-ft W Black High Density Polyethylene Pond Liner (165- Gallons) in the Pond Liners department at Lowes.com
Amazon.com : Pond Liners For Small Ponds Easy To Clean HDPE Preformed Pond Liner Rigid Thickness 7.9mil Fish Pond Liners Sun Protection/ Tear Resistant Garden Pond Liner For Waterfall Koi Fish Pond
MacCourt 3.7-ft L x 2.16-ft W Black High Density Polyethylene Pond Liner (30-Gallons) at Lowes.com