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 marine-grade moisture-resistant HDPE sheets. They won’t HENAN OKAYorb moisture or swell when exposed to humidity.