Winter Cover with cable and winch:The material is PE.Double coated.The quality is best. This pool cover features U.V. stabilized woven polyethylene scrim that protects the winter cover from sun, snow, wind and ice. After summer, when winter is coming,you are not usually use the swimming pool,so you need a winter cover for your pool.It will keep pools clean and free from dirt leaves and debris. Also it prevent water wear and tear,keeps pools clean,stop chemicals loss,and prevent algae growth.Thickness available from 11/100 to 35/100.Comply with the requirement of international standard GB/T 3808-1999