The PS100 combines several electrical diagnostic tools, including an AVOmeter (for measuring voltage, current, and resistance), test light, short circuit indicator, relay/component tester, continuity tester, and bad ground indicatorPerforms every type of service including power injection, measurement, ground testing, polarity checks, continuity testing and components activationEasy to read AVOmeter allows you to read voltage, current and resistanceWith a flip of the power switch, you have an instant hot/ground lead for powering up electrical components like cooling fans, and relaysSimultaneously uses the hot lead and the ground lead to activate components right in your handCircuit breaker protectedInstantly identifies positive, negative and open circuitsTests for bad ground contacts instantly, allowing you to follow and locate shorts fast without wasting fusesInstantly checks continuity of switches, relays and diodesBuilt-in FlashlightAudio tone indicator allows for no-look menu scrollingSturdy blow-molded case, 20ft cable, cabled battery clamps, cigarette lighter power adapter, and ground connector