Federal Signal 450D Category : Federal Signal Simplex rebranded this alarm for a little while. Brand Federal SignalModel 450DManufacturer Federal SignalType Alarm (Horn)
Simplex 4050 Category : SimplexThis horn runs on AC power and goes with my the Simplex 4050-001 light plate.
EST SD-TRK4 Category : EST/EdwardsThis test switch is equipped with power, alarm, and trouble lights, and operates using an EST CAT 45 key.