For use with fire rated pairs of doors. Automatic flush bolts are projected and retracted without any manual operation required. When the active leaf is opened, the flush bolts are retracted, allowing the inactive door to open. When the active leaf is closed, the flush bolts are automatically latched again. Fully automatic - bolt retracts when active door is opened; bolts extend when active door is closed. This automatic latching is accomplished by a small spring-loaded button on the edge of the flush bolts which, when depressed, will extend the flush bolts and remain latched. When the active leaf is opened, these buttons will protrude from the edge of the door which pulls the flush bolts to the retracted position. When the active door is shut again, it will push these buttons and cause the bolts to re-latch.