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5/8 in. (15.9 mm) Sheetrock ® Brand EcoSmart Panels Firecode ® X (UL Type ULIXTM) represent a revolution in wallboard manufacturing, reducing the use of natural resources and impact on the environment. These lightweight 5/8 in. (15.9 mm) enhanced proprietary Type X gypsum panels have been formulated to achieve all of the same strength and performance characteristics as standard 5/8 in. (15.9 mm) Sheetrock ® Brand Firecode ® X Panels at a lower environmental impact and reduced weight. They feature an innovative noncombustible gypsum core that is encased in 100% recycled face and back papers that form a high strength-to-weight ratio composite design. The face paper is folded around the long edges to reinforce and protect the core, and the ends are cut square and even. The long edges of the panels are tapered, allowing joints to be reinforced and concealed with Sheetrock ® Brand joint treatment systems. The panels are UL Classified for fire resistance and can be used in any UL Design in which UltraLight Innovation Type X (ULIXTM) panels are listed. On the face along the long edge of each panel, the UL Type Designation is printed for easy identification by building inspectors.