From the website:
SignalGuys.com is a premier provider of industrial signal and communications equipment. Your source for alarm horns, strobe lights, andon lights, bells, sirens, communication equipment, machine alarm devices, rotating lights, LED alarm lights, speakers, amplifiers, explosion proof strobes, explosion proof speakers, hazardous location signals, backup alarms, panel alarms, indicating lights, amber beacon lights, and other signaling and communication devices.