The 2157280 is a Fluke 1587/1577 Insulation Multimeter that combines a digital insulation tester with a full-featured true-rms digital multimeter in a single compact, handheld unit. The device measures insulation resistance from 0.01 MO to 2 GO (model 1587) or 0.1 MO to 600 MO (model 1577) with selectable test voltages of 50 V, 100 V, 250 V, 500 V, and 1000 V for the 1587, or 500 V and 1000 V for the 1577. It features live circuit detection that prevents insulation testing if voltage exceeds 30 V, auto-discharge of capacitive voltage in less than 0.5 seconds, and a large backlit display for easy reading. The multimeter provides AC/DC voltage, DC millivolts, AC/DC milliamps, resistance, continuity measurements, and additional functions such as capacitance, diode test, temperature, and frequency measurement (1587 only). With CAT III 1000 V and CAT IV 600 V safety ratings, rugged construction, and a three-year warranty, this instrument is ideal for work on motors, generators, cables, and switchgear in both troubleshooting and preventative maintenance applications.