A flashing or strobing light triggered by an intercom's "Call Signal," used to alert someone who does not normally wear a headset (especially Monitor and FOH engineers).
http://www.beltpack.com/blazon4.html
Clear-Com FL-7 Call Signal Flasher
For less obtrusive uses, an LED fitted into an XLR connector:
http://www.nifty-gadgets.com/Com-bits.htm
http://www.beltpack.com/blazon4.html
Clear-Com FL-7 Call Signal Flasher
For less obtrusive uses, an LED fitted into an XLR connector:
http://www.nifty-gadgets.com/Com-bits.htm