Heavy duty tester signals with a light and buzzer. The test kit test low voltage up to 28 volts. Also performs these functions: Find electrical shorts, checks polarity, detects battery drain, checks circuits from a distance. Heavy-duty coil cord extends over 8 feet. Detachable, spring-loaded hook pulls center of the wire into the probe every time. Attach alligator clip to the probe when a clip-on connection is needed.