Protect pools in the winter months with Heritage Deluxe Winter Covers for 27 Round Pools. They are made with a strong woven triple-laminated polyethylene that s treated against destructive UV rays for long-lasting durability. Heritage pool covers feature plastic coated cables that weave in between the aluminum grommets every 3 to 4 and tighten with the ratchet kit provided for easy application. The navy blue or green top and black bottom design is light restrictive to resist algae and bacterial growth. These polyethylene pool covers are 3 larger than the pool themselves allowing them to come over the top and down the sides providing full coverage. Use a 4 x 8 inflatable pillow and stainless steel winter plate with this product for best results. Stop snow rain and other forms of precipitation from leaking in with this protective top.