Sun2Solar Blue 21-Foot Round Solar Cover | 800 Series | Heating Blanket for Above-Ground Swimming Pools ATTRACTIVE BLUE DESIGN - Sun2Solar solar blankets are made from a film of thousands of tiny bubbles, which work together to collect and retain heat both at night and on those chilly days. The blue color provides an appealing look while also using the suns rays to help warm your swimming pool. MINIMIZE WATER EVAPORATION - The use of a solar cover helps in preventing up to 95% of pool water evaporation. When not enjoying a refreshing swim, keeping your pool covered lessens the vast amount of water lost into the environment. Fill up your swimming pool less and enjoy it more! JUMP INTO WARMTH - Show friends and family your bravery by jumping in without the standard toe dip. Enter the swimming pool confidently knowing the Sun2Solar solar cover has kept the water warm just for you. Its easy to put on and take off allowing more time for showing off HEAT RETENTION - After everyone has called it a day with wrinkled fingers from too much fun in the sun, make sure to place this solar cover back atop the water. Dont lose all of that warmth generated throughout the day when the sun sets. Assure your pools temperature does not drop too much by protecting it at night through use of a solar blanket TRIM TO FIT - Your pool may be uniquely shaped and getting the right fit is as easy as finding a marker and sharp pair of scissors. Have the bubbles facing down to the water and trace a line on the cover showing where you should cut off the additional material. Do so confidently knowing this wont affect the manufacturers warranty---they understand