USG Securock® Brand UltraLight Glass-Mat Sheathing are lightweight, noncombustible, moisture- and mold-resistant panels designed for use under exterior cladding where conventional gypsum sheathing products have traditionally been used. They have been formulated to achieve all the strength and performance characteristics as standard USG Securock® Brand Glass-Mat Sheathing at a significantly reduced weight. Example applications include under brick veneer, properly detailed Exterior Insulation Finish Systems (EIFS), clapboard siding, panel siding, shingle siding, shake siding and conventional stucco.