The Brinks Commercial Commercial Entry Knob features push and turn button locking. Push interior button to lock the exterior door knob until it is unlocked with use of key or by turning interior knob. The deadlocking latch bolt is operated by the inside lever at all times. This lever fits doors 1-3/8-in to 2-in thick. It has a 3 hour UL fire rating and meets or exceeds ANSI Grade 2 standards. Brinks Commercial is the pro's choice for commercial door hardware.