Our Classic Series above ground solid winter pool covers are constructed of heavy-duty polyethylene with extra material or ‘overlap’ that extends beyond the pool size. This overlap helps ensure complete coverage of the entire pool. Edges are either self edged with double chain stitching or reinforced with a stitched on 1.5” binding for strength. The covers’ topside has been treated to inhibit damaging UV rays and the bottom sides are black to reduce algae growth.