• For Install On Walls, Countertops And Fireplaces • Great For Tub Surrounds, Walk-In Showers And Building Benches • 100% Waterproof XPS (Extruded Polystyrene) Core Is Resistant To Vapor Pressure And Does Not Support Mold Growth • Offers Support For Large Format Tiles • Non-Deteriorating Properties • Flame Retardant • Premium Polymer-Modified Thinset Mortar Required For Installation (Premixed Mortar Or Mastic Are Not To Be Used) • Mfg #TT8016RED10 • "Pkg Of 5"