Two-Layer Construction of Specially Reinforced, Laminated, High-Density Polyethylene Fabric, Water, Rot, and Mildew-Resistant, Crack-Resistant to -20 degree Fahrenheit, Rustproof Grommets on Each Corner and all Around hem, Poly Roping Sewn into Hem all Around for Extra Strength, Tough with Reinforced corners, All-Purpose Utility Covers, 14 x 14 Weave (200 percent Denser than Reg. Grade), Solid Brass Grommets every 18" Around Hem and at Every Corner, Black Polycast Reinforcement Bars on Corners, Silver on One Side, Black on the Other - Silver Side Reflects Light and Heat, UV-Resistant Treated Fabric, 8" X 10" Double Duty Silver/Black Tarp.