Our durable spa solar blankets can warm your spa this year by up to 15°f. These blankets are made to give you maximum heating properties combined with long life. Our 12-mil blankets 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 your spa for optimal heating. All of our blankets are U.V.-protected so they last under the most intense sunlight. Warm up your spa this season with our Spa Solar Cover.