USG Sheetrock® Brand Mold Tough® AR Firecode® Type X Panels are available in UL Type Designation AR, and were designed and tested to offer greater resistance to surface indentation and impact damage than standard USG Sheetrock® Brand Gypsum Panels. These panels are a low-cost alternative to other systems for partitions that require greater impact resistance, are UL Classified as to fire resistance and meet the requirements for Type X in the model building code. USG Sheetrock® Brand Mold Tough® AR Firecode® X Panels have a noncombustible, moisture-resistant core that is encased in moisture- and mold-resistant, 100 percent recycled green-face and brown-back papers. 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 joint treatment system.