Small Pond Liner, 4 x 7 Feet 20 Mil Liners for 4-Foot by 7-Foot, Black

EASY TO CLEAN - The koi pond liner provides a flat surface for your pond, reducing the soil accumulation. THICKER - Pond liner 20 mil, thick pond liners for outdoor ponds; Ultra-durable yet lightweight, easy to install, while flexible for a variety of creative designs.

eBay