Viking Electronics VK-LM-1A Universal Message Waiting Light

-Compatible with any telephone system with standard DC message waiting voltages ranging from 90VDC to 120 VDC
Fully modular for quick plug-in installation by non-telephone personnel
Unit's LED will blink at a steady rate when the message waiting voltage is detected.
Flickers when the phone rings
Attractive styling
Easy retrofit mounting
Works with nearly all message waiting voltages
Not compatible with any AT&T phone system