The Greenlee CM-660 (52066379) True-RMS AC Clamp Meter, 600A AC, 600V AC/DC, is a hand-held testing device with the following measurement capabilities: AC and DC voltage, AC current, AC current AmpTip, frequency, non-contact electric field (EF) detection, and resistance. It also checks diodes and verifies continuity. The meter is designed to be placed on or removed from insulated or uninsulated conductors.