Blue Wave NS098 12-mil Solar Blanket for Hot Tubs, 7-ft x 8-ft, Royal Blue EXTENDS THE SEASON - This 12-mil solar blanket uses passive solar heating to increase the temperature of your hot tub up to 15 degrees Fahrenheit. SAVE ENERGY - The insulating thermal bubbles trap heat while the transparent blue color lets in maximum solar rays, making this cover energy-efficient all summer long. UV-RESISTANT - The rectangular 7-ft x 8-ft Spa Solar Cover is designed to withstand exposure to chemicals and UV radiation and will tolerate even the most intense sunlight. REDUCE EVAPORATION: Prevent up to 95% of water and chemical evaporation with the use of a solar blanket. This reduction of evaporation is not only environmentally friendly, it will save you time and money, as well. 90-DAY WARRANTY - Your product comes with a 90-day manufacturer warranty.