Pushbutton Lock 2835-SC-DC is mechanical, keyless lever lock double sided combination, with Passage Function and Satin Chrome finish. Lever handle is installed on exterior and interior side of the lock body. 2835-MG-DC is bump proof, pick proof lock that does not require wires, batteries or electricity. This is a MARINE GRADE double sided combination lock and is ADA Compliant. It has auto-locking with passage function or can be set to lock everytime the door closes. The passage function allows the springlatch to move freely, in and out, until you lock it again. Also the 2835-SC-DC has adjustable latch and reversible handing. It is dedicated to exterior or interior using. Mounts in standard 2 1/8" hole. One user code with thousands of possible combinations works as a lock key. The mechanical pushbutton lock requires no wires, batteries or electricity. Locks fit doors 1 3/8" to 2" thick with a 1 1/8" backset. The Pushbutton Lock is very easy and quick to install - installs in minutes with EZ plates and very easy to change code. For thicker doors, an Extension Kit is available - extensions for doors up to 5? in width. These provide keyless security, fit most doors and are weather resistant.