Cal-Royal NM8453 Heavy Duty Grade 1, Entrance - F20 - mortise lock Latch bolt retracted by key outside and inside lever when outside lever is locked. Outside lever retracts latch bolt unless outside lever is locked by operating toggle button. Outside lever is locked and unlocked by toggle button. Key outside locks outside lever only. When latch bolt is retracted by inside lever, outside lever remains locked. Auxiliary latch deadlocks latch bolt when door is closed. Inside lever is always free for immediate exit. Features For Doors - 1-3/4" thick Backset - 2-3/4" Lockcase - Heavy gauge zinc chromate steel Front - Heavy gauge steel 8" x 1-1/4" x 3/32". Accommodates flat doors & doors beveled 1/8" in 2" Armored Front - Wrought brass attached by machine screws to lockcase front Deadbolt - 1" throw, brass, chrome plated with hardened steel rollers Latchbolt - Brass, chrome plated with heavy-duty deadbolt Guardbolt - Extruded brass, chrome plated Stopworks - Rocker type, brass, chrome plated Strike - Brass, non-handed curved strike 4-7/8" x 1 1/4". Curved-up strike available upon request Handing - Handed. Easily field-reversible UL Listing - UL Listed A Label (3 hours), for use on fire doors, single or pair of doors. F mark stamped on strike ANSI/BHMA - Meets ANSI/BHMA A156.13, Series 1000, Operational & Security Grade 1 Standards. Lock body conforms to Federal Specification Type 86; and all dimensional and operational performances, exceeds 1,000,000 cycles Escutcheon Dimension - 2 1/2" W x 8 1/4" H x 1/2" T Description BHMA Certified Lifetime Warranty, GRADE 1 Conforms to federal specification type 86; and to all dimensional and operational performances of ANSI A156.13-1 80, Series 1000, Extra Heavy Duty UL listed 3-hour rating, conforms to standards UL10C and UBC 7-2-1997 Optional Interchangeable Core Rust-proof heavy duty 2 3/4" backset lock case Individual spring to prevent lever sag, easily reversible Forged brass lever handles exceed requirements of ADA (American Disability Act) Auxiliary latch bolt Armored front plate conceals lock mounting screws 1" throw heavy duty deadbolt with anti-saw hardened pins Heavy duty 3/4" latch bolt with anti-friction latch, easily reversible Optional Electrified Locks available Conforms & Meets ADA Regulations