Alpha TSMBB Bus Speaker/Microphone, Brown Used with Ht3011 Type S.T.R. 2 Wire ‘Bus’ Handsets Only and Modular Style Panel(S)

The TSMBB speaker/microphone designed to be used with modular series door entry stations. It features a weather-resistant speaker, long-life electret condenser microphone, illuminated drycontact low voltage light pushbutton and plug-in connector for easy wiring. It is 3.94″w x 3.94″h (100mm x100mm), and is made to snap into the MT series modular panel trim frame(s). To service it, once installed, use the model 13510 key / tool unit.