The Pool Mate Professional-Grade Blue Winter Pool Cover will protect your pool from all winter elements. This is a solid winter pool cover that will not allow water to pass through its material. The Pool Mate Professional-Grade Blue Winter Pool Covers is constructed of professional-grade polyethylene. All seams are heat sealed for better performance. This cover is constructed with Rip-Shield Technology that will prevent small rips from becoming larger tears. The blue topside of this pool cover is coated to prevent UV damage. Includes perimeter binding. Please order by your pool size, as the overlap goes beyond the pool size listed. This cover includes a four-foot overlap. If you have a very large top rail, please consider a larger pool size. This cover should be able to comfortably float on the pool water without excessive stress. This cover is not meant to be used as a debris cover during the swimming season. This winter pool cover is intended to be used during the off-season. This cover is meant for traditional above ground pools with a traditional top rail. Includes a winch and cable that should be used to secure your pool cover through the grommets around the perimeter of the pool cover. For extra securing, cover clips and cover wrap (both sold separately) are suggested for pool closing. No other method of installation is recommended. Includes a twenty year warranty.