Aquabuddy 10 x 4M Solar Swimming Pool Cover - BlueMade of premium low density polyethylene 400 Micron this solar pool cover is extremely durable and can efficiently and effectively distributing the heat to the water. It allows sun heat to penetrate to the pool increasing the temperature in the water as well as can significantly reducing water evaporation. Also it helps in keeping the pool clean reducing maintenance time and cost for filtration and pumping.