Bestway Fast Set Solar Pool Covers use the suns energy to maintain and increase the water temperature of your pool. By absorbing the sunlight, these Fast Set Solar Pool Covers transfer the heat generated to the water.. . . . The above ground swimming pool cover is made from a durable material similar to the bubble wrap used in packing. These tiny air bubbles help to insulate a Bestway pool by trapping heat inside it and warming the water. They can also transfer heat by absorbing sunlight. The air bubbles in the fast set solar pool cover also serve to insulate your pool, helping to reduce water temperature loss whilst also preventing dirt and debris from accumulating in the pool.. . . . Whats more, having a pool cover helps to reduce evaporation and, because it shields from dirt and grime, can reduce the need for water cleansing chemicals, saving quite a few pennies over the course of the summer. The solar covers bubble design can keep a pool insulated even when the sunny season has finished, prolonging the use of an above ground pool for weeks or even months after!. . . . Setting up the solar swimming pool cover couldnt be simpler. When an 8ft Fast Set pool isnt being used you just spread it out on the water. Theres no need for tie ropes because it floats on top! This item measures 82 inches as it sits inside the top of the fast set pool. Safety Information:Warning. Not suitable for Children under 3 years. Bestway Solar Swimming Pool Cover (8')