USG Sheetrock® Brand Firecode® Core Gypsum Panels are the original, most widely used gypsum panels on the market. The face paper is folded around the long edges to reinforce and protect the core, and the ends are square-cut and finished smooth. Long edges of panels are tapered, allowing joints to be reinforced and concealed with a USG Interior Finish System. Sheetrock Brand Firecode Core 5/8 inch Type X Gypsum Panels are available in one thickness: 5/8 inch Panel, UL Classified (Type X), and are recommended for application in fire-resistance rated construction.