System Sensor 5601P This is a 135F rate of rise and fixed temp heat detector. Brand System SensorModel 5601PManufacturer System SensorType Heat Detector
Potter OSYSU-A2 Category : PotterI honestly have no idea what this thing is, but it says Potter on it, so that means it goes...
Gentex GX90S-4-15/75WR Category : GentexI also have the version of this alarm that is rebranded by Simplex.