The 4920AN-46-602-628 series Deadlatch provides precise traffic control and straightforward installation for hollow metal or wood doors that have been prepped for hardware in accordance with ANSI regulations (ANSI). A door can swing freely for some of the day and only be opened for exit when the bolt is free to latch thanks to a function that is controlled by a key. This enables clients or guests who are already inside the property to use a "locked" entry as an exit. Turn the key to operate it, or pull the handle to retract the spring-loaded latchbolt. Push the bolt in and turn the key backwards to secure it in the retracted position. It is simply convertible with any MS1850A or MS1850S Deadlock that has the identical backset and faceplate shape without requiring any design modifications. It also takes the place of ANSI Deadlatches 4520 and 4720.