The Lowe 153 full mortise office lock is available in 2-1/2”, 2-3/4”, 3-3/4”, 5” or 6” backsets. Typically used as an office lock, access is controlled via the thumb turn which switches the lock between the locked and unlocked position. From the inside free egress is always available. The lock can be configured at the factory to be used with knobs, levers, thumb latches or any combination thereof. It is supplied with a strike plate and stamped metal dust box, and the faceplate has an adjustable bevel. Center dimension between the handle and thumb turn is 2-7/16”. The 153 is ANSI Grade 1, and is UL listed with a 3 hour fire rating. Available in all finishes.