Arctic Armor winter pool covers are woven from strong and long-lasting polyethylene tapes to produce a pool cover that will hold up to winters worst. Arctic Armor above ground and in ground winter pool covers don't skimp on fabric! They are constructed using an extra foot of material another great value! A 4" overlap provides a better fit on above ground pools, especially those with wider top rails, and secures better on the pool deck for in ground pools. This extra foot also takes up some of the slack during windy winter weather, helping to prevent excessive wear and tear. Arctic armor winter pool covers are constructed of an extremely tight weave fabric which does not allow light to pass through. Without sunlight, algae cannot grow! Give your cheap pool covers the light test today!