Brass mortise lock with a narrow back set of 1 3/4". This mortise lock is available in 3 different finishes. The lock box measures 4" tall, 2 1/2" in depth and 1/2" thickness. The distance from the center of the knob hub to the center of the round part of the keyhole is a standard 2 1/4". The lock face plate measures 6" tall by 7/8" wide and the strike plate measures 5 1/8" tall by 1" wide. Both the lock face plate and strike plate are solid brass.