UNI-T UT18C Auto Range Voltage and Continuity Tester with LCD/LED Indication Date Hold RCD Test and No Battery Detection Suitable for: smelting, electronics, manufacturing, defense, electric power, petroleum, chemical industry. phase of three-phase AC power indicator Measuring Range:12V/24V/50V/120V/230V/400V/690V UT18 series of test pen with measuring AC and DC voltage (including the three-phase alternating current) measurement no battery detection and other functions