Climate Shield is designed to protect for years, through all types of weather (sun, rain, and extreme sun). Climate Shield will extend the life of your Pool Heater or Heat Pump. Each cover is made of heavy, high quality vinyl and lined with a white non-woven cloth material to absorb moisture and prevent vinyl from sticking to equipment (even in the hot sun). In addition, vented panels (one on each side ) of the cover allow the cover to breathe and prevent moisture build up.