This 20 7/8 inches by 12 3/4 inches polycarbonate hotel food pan is a standard size which fits into universal racks, heating elements and walk-in coolers. This standard was intended to rationalize the working processes in food industry operations by creating a high level of compatibility of kitchen equipment. The Palermo series is a part of a lineage of cookware more than 80 years old. It is NSF approved.