Power Probe’s Power Probe III features an easy-to-read backlit voltmeter for reading voltage at the tip. 42V ready, it has rugged, gold-plated connectors for more secure connections. A standard 4mm cap ensures full compatibly with the company's Gold Series leads, as well as all other 4mm leads, plugs and jacks. Pressing the unit’s rocker switch forward provides a hot lead for powering up electrical components like cooling fans and relays. Moving the switch rearward provides an instant ground lead. Simultaneous use of the hot lead and ground lead will activate components right in the user’s hand. With the polarity tester, positive, negative and open circuits can be identified without having to re-polarize or reconnect hook-up clips.