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Sheetrock ® Brand Ultracode ® Core Panels (UL Type ULTRACODE) are 3/4 in. (19.1 mm) Type X panels that can provide 1-4 hr. fire ratings with fewer layers of gypsum panels than are typically required when used in approved applications. These enhanced fire-resistant gypsum panels feature a noncombustible gypsum core that is encased in 100% recycled face and back papers that form a high strength 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 Type ULTRACODE 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.