Fail Safe DBR-SAF. This DBR range electric release accepts a 13mm deadbolt and has bolt status output indicating bolt locked or unlocked status. It can be fitted both horizontally or vertically and is tested to 500,000 cycles. Two versions are available: Fail-Safe (power to lock) or Fail-Secure (power to unlock).. Accepts 13mm deadbolt. Horizontal or vertical fitting. Monitored bolt status indicates locked or unlocked. Operating voltage 12Vdc