Handy Electrical Troubleshooting Kit Performs 5 Functions. Circuit breaker finder with outlet/GFCI tester, continuity checker/wire tracer and AC voltage detector with flashlight in one convenient kit. Quickly locate Circuit Breakers with audible and visual alert. Variable Sensitivity adjustment to pinpoint correct circuit breaker. Continuity testing via bright flashing LED and loud pulsating beeper. Remote probe with flashing (red/green) LED allows a single user to three cables. Includes CB10, CT20 and DV20 AC voltage detector/flashlight.