AEMC Instruments has developed the model CB-1 automatic circuit breaker identifier to enable fast identification of branch circuits at the circuit breaker or fuse panel box. The transmitter is plugged into the receptacle and the receiver is passed over the circuit breakers or fuses. A tone will be heard as the correct breaker is scanned. Power does not need to be interrupted and no other adjustments are necessary. The CB-1 operates on 90-120VAC, at both 50 and 60Hz. AEMC INSTRUMENTS Boston, MA