Siemens U-MHU-MCS I believe that this alarm is capable of doing multiple tones. Brand SiemensModel U-MHU-MCSManufacturer SiemensType Alarm (Horn/Strobe)
EST SIGA-278 Category : EST/EdwardsThis unit is rusting ever so slightly. It features a newer EST logo on it.
System Sensor 4WT-B Category : System SensorThis 4-wire smoke detector also has a thermal heat sensor.
Wheelock MT-12/24 Category : WheelockThis signal, I believe, can be used for general application purposes, as well as fire protection.
