OX Insulated Sheathing starts with a non-reflective resilient exterior facer that provides water resistance and high durability. The closed-cell, moisture-resistant polyisocyanurate foam core provides high compressive strength, a long-term R-value and a continuous air barrier. And a thin, high-pressure laminated member provides even more structural support. Put it all together and you get the highest possible performance from your structural sheathing.