Firestone ISO 95+ GL insulation consists of a closed-cell polyiso foam core laminated to a black glass reinforced mat facer on both major surfaces. ISO 95+ GL insulation provides outstanding thermal performance on commercial roofing applications, while providing positive rooftop drainage to help eliminate ponding water when tapered ISO 95+ GL insulation is used. It also offers high-energy efficiency through the highest R-value ratings per inch versus other insulation materials and Compatible with all types of commercial roofing systems, easy-to-handle, lightweight insulation is especially suited for direct application.