USG Sheetrock Brand EcoSmart Panels Firecode X (UL Type ULIX) are 5/8 in. enhanced proprietary Type X gypsum panels that have comparable strength and performance to standard 5/8 in. Type X panels, while also being significantly lighter and more environmentally friendly. These UL Classified panels can be used in any Design where UltraLight Innovation Type X (ULIX) panels are allowed. The UL Type Designation is clearly printed on each panel for easy identification by building inspectors. These panels are ideal for both commercial and residential applications, including load-bearing and nonload-bearing fire-rated walls and ceilings.