The HT79 clamp meter is primarily designed for measuring leakage currents of AC and DC, as well as currents up to 10 A (DC) and 20 A (AC) according to CAT IV 300 V standard IEC/EN61010-1. It also measures voltage, resistance, and circuit continuity for AC/DC. The device features a 5000-point display, backlight, and auto power-off to conserve internal battery. It can clamp conductors up to 23 mm in diameter. Key functions include MIN/MAX for maximum and minimum readings, data hold, and ZERO for zeroing currents.