Green. 4X8 sheet. Thickness: .078". A great way to create a moisture-resistant barrier behind showers. This is the "Green" one-Light Structural Grade. Thermo-ply is a code-approved exterior structural sheathing, water resistive barrier and air barrier. Composed of pressure laminated plies consisting of high-strength cellulosic fibers. These fibers are specially-treated to be water resistant and are bonded with a proprietary water-resistant adhesive. A protective polymer layer is applied on both sides of the panel, and foil facings may be applied on one or both faces. R-value is 0.13.