The Pool Mate 12-Year Winter Pool Cover will protect your pool from winter elements. This is a solid winter pool cover that will not allow water to pass through its material. The Pool Mate 12-Year Winter Pool Covers is constructed of strong polyethylene. All seams are heat sealed for better performance. This cover is a magnesium color. Please order by your pool size, as the overlap goes beyond the pool size listed. This cover includes a five-foot overlap. Please order a larger size cover if you have steps (or any other irregularity) protruding from your pool. Water tube loops are placed around the perimeter of the pool cover. Water tubes sold separately. Only water tubes should be used to install this pool cover. No other method of installation is recommended. 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. Includes a twelve year warranty. This cover does not have a black underside.