Our Classic Series above ground solid winter pool covers are constructed of heavy-duty polyethylene material with extra material that extends beyond the pool size. This additional material helps ensure complete coverage of those pools with larger top rails. Edges are either self edged with double chain stitching or reinforced with a stitched on 1.5” binding preventing wear and tear. The covers’ topside has been treated to inhibit damaging ultra-violet rays and the bottom sides have been treated to prevent the growth of algae.