USG Sheetrock® Brand Ultra Light Panels Firecode® X (UL Type ULX) are 5/8 in. (15.9 mm) Type X gypsum panels formulated to achieve all of the same strength and performance characteristics as standard 5/8 in. (15.9 mm) USG Sheetrock® Brand Firecode® X Panels at a reduced weight. These lightweight panels feature a noncombustible gypsum core that is encased in 100% recycled face and back papers. 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 USG Sheetrock® Brand joint treatment systems. The panels are UL Classified for fire resistance and can be used in any UL Design in which Type ULX 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.