Simplex E2031LL-626 Satin Chrome US26D Grade 1 E-Plex Cylindrical Lock With 1/2" Throw And 2-3/4" Backset, specially designed to provide exterior access by combination, while allowing free egress. The electronic push button lock eliminates problems and costs associated with issuing, controlling, collecting keys and cards, and it stores up to 100 different access codes which are programmed via keypad or with the optional Microsoft Excel based software. This lock uses three AA Batteries that load into a slide up battery tray in the outside housing. The lock does not require any wiring to or through the door, and it has a no key bypass. This lock is a heavy duty commercial grade 1 lock set, with a 1/2" throw latch, a 2-3/4" backset, it fits doors 1-3/8" to 2-1/2" thick, it is fire resistant and ADA complaint. This lock is constructed of solid cast exterior housing, solid cast levers, and the cylindrical drive wear was tested for extensive use in indoor and outdoor applications.