In The Swim 12-Year 18 x 33 ft Oval Pool Winter Cover All seams are heat-sealed (not sewn) to prevent water from seeping through the cover Triple laminated poly-constructed inner scrim is topped by a premium weather resistant top coating Comes complete with heavy-duty vinyl coated cable and winch Pool cover color is dark green with a black underside to inhibit algae growth Order by pool size, cover accommodates an 18-inch water drop