Thermo-Shield® Exterior / Interior Wall Primer is a water-based elastomeric coating and sealant made from 100% acrylic resins. This extremely durable, penetrating sealant is specifically designed with tenacious adhesion to be used as a prep and prime coat and/or to restore coarse or highly weathered surfaces. This product is made with mildew resistant agents and is highly resistant to the sun’s ultraviolet rays. Thermo-Shield® Exterior / Interior Primer is a permanently flexible, breathing membrane (Vapor Permeable), allowing moisture from the substrate or building interior to escape, while remaining impervious to water penetration from the exterior.