WRM1074 Features: * Recommended when installing your TempZone floor heating system over a concrete slab * Can be set under tile and stone, over any acceptable sub floor * Up to 25 times lighter than 1/4"" backer board * Heat and cold resistant, and will not rot, support mold and mildew, or absorb moisture * Stable and durable, remaining unchanged after repeated impact loads Specifications: * Square Feet: 8 sq. ft Dimensions: * Width: 24"" * Thickness: 0.25"" * Length: 48""