Above Ground Pool Liner Pad — 1/8" Polyester Geotextile — Fits 21' Round & Sizes 15', 18', 21', 24', 27', 12'x24', 15'x30', 18'x33' — White

Made from 1/8" thick polyester geotextile, this pad is resistant to almost any penetrating object and provides heavy-duty protection against undergrowth. The pad arrives precut to your pool’s size, so no cutting or trimming is required. It adds an insulating layer to help reduce heat loss into the ground and creates a smoother floor surface for your liner. Replace this pad each time you change the pool liner.