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 5 ft. overlap. The Dura-Guard winter cover features 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 4 ft. 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.