The UNI-T UT501A is a digital insulation resistance tester used for measuring the insulation resistance of electrical equipment, household appliances, and electrical circuits.

1:  It can also measure AC voltage.
2: It features multiple test voltages (100V, 250V, 500V, and 1000V), a wide resistance measurement range (up to 5.5 GΩ), a clear LCD display with backlight, and safety features like auto discharge and high voltage indication.
3: It's a reliable tool for electrical maintenance, testing, and inspection.