The Bever-mortice lock “Turrus” with its “Pull-fast blocking device” is an essential safety element in the overall plan of
the corridor door safe guarding. In addition to its other safety elements like the dead locking latch as well as the safety
device against back-pushing of the bolt, the “Pull-fast blocking device” is working especially against the wide-spread
burglary procedure which uses the so-called “Pull-fast”- or “Screwdriver”-method.