This solar pool cover sits directly on the water surface within the pool's edges, and can raise the temperature of your pool water by up to 10 degrees, depending on the amount of direct sunshine.With PE air chambers all over its surface, it has excellent heat-retaining properties. It is the least expensive way to heat your swimming pool. At the same time, it helps reduce the use of chemicals, as well as water evaporation.It is lightweight and easy to install and manage. Delivery includes: 1 x solar pool cover measuring 216 inchesColor: BlueDiameter: 216 inchMaterial:Thick PE film with air chambersShape: RoundFabric: PVC: 100%