Fail-unlocked 37
The electric strike is locked for as long as the power is on. If the power is switched off or if there is a power cut, the keeper can be moved and the door can be opened.

Electric strike 37
Adjustable keeper (FF, FaFix®), Fail-unlocked

Electric strike 37RR
Adjustable keeper (FF, FaFix®), Monitoring contact (RR), Fail-unlocked

Electric strike 3705
Adjustable keeper (FF, FaFix®), Diode (05), Fail-unlocked

Electric strike 3705RR
Adjustable keeper (FF, FaFix®), Monitoring contact (RR), Diode (05), Fail-unlocked