Recycled Marine-Grade Moisture-Resistant Polyethylene (HDPE) Sheets. lor: Black. Maximum Temperature: 180° F. Tensile Strength: 2, 100 psi (Poor) Impact Strength: 0. 7 ft- lbs./in. (Poor) Hardness: Durometer 68D (Medium) For Use Outdoors: Yes. Made of recycled HDPE plastic, these sheets are more sustainable and Okaynomical than standard