The Robelle Defender Winter Cover is a heavy-duty, UV-resistant polyethylene solid winter cover for in-ground pools. This cover includes five feet of overlap, which will give you ample material to cover your pool. Please order by pool size, as the overlap goes beyond the pool size listed. Please order a larger size cover if you have steps (or any other irregularity) protruding from your pool. The top of this cover is sandstone, and the bottom side is black to prevent algae growth. The Robelle Defender Winter Cover features a heavy-duty 12 x 12 scrim. This cover is constructed with a heavy-duty polyethylene material that weighs 3.26 oz./yard2. Both the scrim count and material weight are good indicators of the strength of your pool cover. A cover with a higher scrim count and heavier material, like the Robelle Defender Winter Cover, will last longer than inferior covers. Heavy-duty water bag loops are placed every four feet. Grommets in all four corners. The Robelle Defender Winter Cover includes a twelve-year warranty.