The ATG-1 Tone Generator emits an audible alert from a small but very loud speaker. The ATG-1 can be hooked to any EI external warning line to immediately alert you to an out-of-redline situation. Generates 4.7kHz tone when an out of limit occurs. The Annunciator Tone Generator may be connected to one or more EI Instruments featuring a waring light (US-8A or SR-8A, C-1P, EC-1P, T-1P, FP-5, R-1, M-1, and OPT-1, etc.) Comes with an on/off toggle switch. Mounts under the instrument panel using wire ties. Operates from 12 or 24 Vdc.