Simplex 2098-9642 I do have two of these heads, but only one of the bases. Brand SimplexModel 2098-9642Manufacturer HochikiType Smoke Detector
EST 882-2B Category : EST/EdwardsThis unit has an electronic horn rather than an electromechanical mechanism.
Pyrotronics ES0-24S Category : Cerberus Pyrotronics, PyrotronicsThis is a rebranded Wheelock horn/strobe, and a pretty rare one at that since it has an electronic horn mechanism...
Gamewell GW-30203-01 Category : GamewellThis is a somewhat obscure Gamewell alarm condition light, most likely used with system components such as duct detectors.