This 25 1/2 inches by 20 7/8 inches stainless-steel baking sheet for 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. All inserts are stackable and have rounded reinforced edges. They are made of 21-gauge, 18/10 mirror-polished stainless-steel. They have seamless construction and are durable, corrosion-resistant and non-tarnishing. They do not react to any food and protect flavors. In addition to in-process control during manufacturing and fabrication, these metals have met the specifications developed by the American Society for Testing and Materials (ASTM) with regard to mechanical properties such as toughness and corrosion resistance. The Palermo series is a part of a lineage of cookware more than 80 years old. It is NSF approved.