Arctic Armor are strong, long lasting tapes of polyethylene tape woven together to create a cover that will hold up against winters worst. This tight weave fabric does not allow sunlight to pass through, stopping the growth of algae. Arctic Armor does not skim on fabric. A 4-ft. overlap provides a better fit, especially on pools with extra wide top-rails. This extra fabric also takes up some of the slack during windy weather, helping to prevent excessive wear and tear.