The Triplett Model CBF200 Circuit Breaker Finder has a unique "comparison mode" to help identify the correct breaker within an electrical panel when signal strengths are very close. In addition, it can detect 6 wiring faults in 3-wire receptacles (Open Ground, Open Neutral, Hot/Ground Reverse, Open Hot, Hot/Neutral Reverse, Hot on Neutral with Hot Open), test the GFCI circuit for proper operation, and has a built-in Non-Contact Voltage Detector (24 to 300V, CAT III-300V) to check for the presence of AC Voltage before working on a circuit. A useful and necessary tool for residential and commercial electricians, home inspectors, kitchen and bath installers, apartment/condo property managers, DIY'ers and handymen. Includes Transmitter, Receiver and 9V Battery. 1 year warranty.