The 5065866 (Fluke 337) is a versatile True-rms clamp meter for comprehensive electrical testing. It accurately measures both AC and DC current up to 999.9 A and AC/DC voltage up to 600.0 V, with True-rms response ensuring precision on non-linear signals. Key features include an inrush current function with a 100 ms integration time to analyze motor start-up, MIN/MAX recording, and a backlit display for visibility in dark environments. The meter also measures frequency up to 400.0 Hz and resistance up to 6000 Ω. With a large 1.2-inch jaw capable of clamping around conductors up to 750 MCM, it is well-suited for industrial and commercial electricians troubleshooting complex electrical systems.