The Robelle Dura-Guard Ultra Winter Cover is an ultra-premium cover for in-ground pools. The dove gray top of this cover is coated with an ultra-premium UV-resistant high-density polyethylene, and the bottom side is black to prevent algae growth. This cover includes five feet of overlap, which will give you ample material to cover your pool. Please order a larger size cover if you have steps protruding from your pool. Includes a premium quality binding around the entire perimeter of the cover that prevents against wear and tear, helps keep grommets in place, and adds to the life expectancy of this cover. The Robelle Dura-Guard Ultra Winter Cover features an ultra-premium 12 x 14 scrim (threads per square inch.) This cover is constructed with an ultra-premium polyethylene material that weighs 4.5 oz./yard2. Both the scrim count and material weight are good indicators of the strength of your pool cover. A cover with the tightest weave and heaviest material, like the Robelle Dura-Guard Ultra Winter Cover will last longer than inferior covers. Ultra-premium quality water bag loops are placed every four feet, and premium grommets are sewn into the water bag loops and at each corner so you can tie this cover down in high wind areas. The Robelle Dura-Guard Ultra Winter Cover includes a twenty-year warranty.