The Megohmmeter Model 653 is a compact, self-contained, hand-cranked True Megohmmeter®. This practical and dependable instrument is designed for a broad range of plant and field service applications, such as acceptance testing and preventive maintenance of wiring, cables, switchgear and motors. The easy hand-cranked operation provides a steady, DC voltage output across the entire range for consistently reliable readings. The Model 653 has three test voltages for insulation resistance testing: 25V, 5V and 1V. Test voltages are generated in full across the entire measurement range.