Product details:
A reverse turn of the key (while bolt is held full retracted) retains the bolt and thus allowing the door to be free swinging with two-way traffic for hospitals, banks, stores, and other buildings which require free entrance at certain times and exit-only at other times. The 4530 series deadlatches are perfectly designed to fit without alteration, the stile cutout for older MS1850 Deadlocks and 4250 Deadlatches of same backset. However, they donot provide the same maximum security level as the MS Deadlock and should not be considered an equivalent replacement.