Wheelock AES-DL1-WS-24 Depending on which set of inputs has power applied to it, the alarm will produce a different tone. Brand Wheelock
Space Age AV32 Category : Space Age ElectronicsI have no idea why there is no fire lettering on this unit
EST 882-2B Category : EST/EdwardsThis unit has an electronic horn rather than an electromechanical mechanism.