The Extech CB10 is an AC Circuit Breaker Finder/Receptacle Tester that locates circuit breakers and checks receptacle wire. The CB10 enables the user to rapidly detect 110 V to 125 V AC circuit breakers and fuses using auditory and visual circuit breaker indicators. The product also has a configurable sensitivity adjustment for pinpointing the correct circuit breaker. This device includes a one-year guarantee, the receiver and GFCI transmitter, and a 9-volt battery for the receiver.