This beautiful tubular construction stainless steel entrance door lock complies with ANSI A156.2, series 4000, grade 2, (400,000 cycles), UL listed for 3 hour fire door. It features a 6 pin SCC keyway with two nickel keys per lock, door range: 1 3/8" to 1 3/4"; backset: adjustable 2 3/8" to 2 3/4" standard; and strike: T strike (1 1/8" x 2 3/4") standard.