Come on in. This beautiful stainless steel passage door lock is made from cylindrical, steel coated with zinc dichromate (corrosion resistance) construction and complies with ANSI A156.2, series 4000, grade 2, (400,000 cycles), UL listed for 3 hour fire door. It features a door range: 1 3/8" to 1 3/4"; backset: 2 3/4" standard; and strike: T strike (1 1/8" x 2 3/4") standard.