The Tell CL100051 Light-Duty Commercial Ball Passage Lock has a satin stainless steel (US32D) finish with a tubular construction. Its performance complies with ANSI A156.2, series 4000, grade 2 (400,000 cycles). It is UL listed for a 3 hour fire door. It has a standard T strike (1 1/8-inch x 2 3/4-inch). Latch bolt is operated by interior or exterior.- Grade 2 cylindrical- 2-3/8″ to 2-3/4″ adjustable backset- Fits 1-3/8-inch to 1-3/4-inch doors