The Dura-Guard pool cover is a heavy-duty solid winter cover. Solid pool covers do not allow water to pass through their material. This winter cover is intended to be used during the off-season. Please order by your pool size, as the overlap goes beyond the pool size listed. Please order a larger size cover if you have steps protruding from your pool. This cover includes a five-foot overlap. The Dura-Guard winter cover features a a heavy-duty scrim count (threads per square inch). The Dura-Guard pool cover has a heavy-duty 8 x 8 scrim. Heavy-duty polyethylene weighs 2.36 oz./yd2. The green topside of this cover is coated to prevent damage caused by the sun's ultra-violet rays and the bottom side is black to prevent algae growth. Heavy-duty water bag loops (water bags sold separately) are placed every four feet. Water bags or water tubes are the only recommended method of installation. The cover should be able to comfortably float on the pool water without excessive stress. Includes a 10 year warranty.