This electrical tester set includes a Circuit Breaker Finder (Cat. No. ET310) and a Voltage Tester (Cat. No. NCVT2P). The Klein Tools ET310 Circuit Breaker Finder with Integrated GFCI Outlet Tester is a digital circuit breaker finder used to locate the correct circuit breaker in a panel to which an electrical outlet or fixture is connected. The Transmitter is connected to the electrical outlet or fixture in the circuit while the receiver is used to scan the breakers in the circuit panel. The Transmitter also features a GFCI outlet tester. The NCVT2P is a non-contact voltage tester that detects 12 to 1000V AC and indicates the presence of voltage in cables, cords, circuit breakers, light fixtures, switches, outlets and wires as well as AC voltage in doorbells, thermostats, low voltage lighting and irrigation systems. Includes both visual and audible signals.