- Emergency alarms (7)
- Burglar alarm apparatus, electric (3)
- Fire alarm apparatus, electric (3)
- Fire detection systems, electric (2)
- Metal detectors (3)
- Sirens, electric: vehicle, marine, industrial, and air raid (1)
- Transportation signaling devices (3)
- Pedestrian traffic control equipment (1)
- Traffic signals, electric (4)
- Intercommunication systems, electric (3)
- Visual communication systems (1)
