The 641 Series door is ideal for openings requiring a counter-type fire-rated door. Common applications include factories, schools, concessions, hospitals, cafeterias and retail settings. Labeled with either a 3-hour Class A rating for masonry applications, or a 1-1/2-hour Class B label in non-masonry fire walls, This door is designed to expand upward in a fire, allowing the guides to be installed flush with the sill. It's compact, box-like form also provides an attractive finished appearance that requires minimum sideroom. The 641 Series exposed components are of stainless steel. This door is also available with a 1-1/2 hour fire-rated countertop with fire-resistant core and a vairty of poplular decorative laminate finishes. Added protection features, such as Fire Sentinel™ and FireLite® vision lites are optional. The 641 Series counter fire door is UL approved and can be custom designed for conveyor openings.