UNI-T UT221 is a safe and reliable 3 5/6 bit AC and DC digital clamp meter with stable performance. It is a professional tool for electricians with a wide range of features and possible use cases. The device has a large-scale integrated circuit and dual integral A/D converter as the core and provides full-range overload protection and novel structural design. UT221 can measure AC/DC voltage and current, resistance, capacitance, frequency, duty cycle, and temperature. It also has a diode test, continuity test, and inrush current measurement function.