These durable above-ground covers can warm your pool this year by up to 15°F. These covers are made to give you maximum heating properties combined with long life. The 8-mil covers are loaded with thermal bubbles that retain heat at night and on cool cloudy days. Transparent blue color allows the maximum amount of solar rays to reach you pool for optimal heating. All covers are U.V.-protected so they last under the most intense sunlight. Built to last and backed by a 3-Year Warranty.