Weakened “teeth” of the bar protect a lock from being forced by a “svertysh”. Svertysh ("bear") is a Г-shaped steel hook for breaking lever locks by means of force. Malefactors' actions are rather simple in this case - they widen a keyhole with a drill, insert the hook and turn it with force in order to make the stand of the bar to bend levers' lugs. After that the lock is opened. In spite of simplicity of the way it is considered criminal, because the crime is prepared - you produce a svertysh and take it with you.

To protect a lock against safecrackers there are weekened "teeth" placed on the bar. Then, when trying to turn a svertysh the teeth will be broken and the lock will remain closed. The thief will not enter a flat, but the owhers will not be able to open the lock with their key either. More often after unsuccessful attempts of breaking you will have to resort to the help of MES. But the cost of a new lock can not be compared with your losses in the case of a successful burglary.