The GMP3Z lock protection is used in conjunction with a GM7xx seismic detector to monitor safe and strong room doors with exposed keyholes. A micro-switch fitted in the swivel plate monitors every movement of the swivel arm and triggers an alarm when unauthorized access is attempted. The swivel arm is made from hardened steel and fully covers the keyhole when the system is armed. When the system is disarmed, the swivel arm can easily be rotated by 90° to enable unimpeded access to the keyhole. The Z shaped swivel arm of the GMXP3Z allows installations on even larger lock roses that protrude up to 24mm.