The Heritage Heavy Duty above-ground pool winter cover is made with a solid 12 x 12 weave and comes with a 12 year warranty. Triple-laminated and poly treated against destructive UV rays this winter cover is built for long-lasting durability. This Pool winter cover features grommets every 3 ft. and includes cable and ratchet kit. The top of the cover is green with a black bottom which is light restrictive to resist algae and bacterial growth. This cover is 4 ft. larger than the actual pool size to accommodate water drop.