Features: 1. Rotary field meter, test plug LED tester can display phase, buzzer display status and instructions. 2. Equipped with a practical carry bag, easy to carry; quick and accurate testing; high safety. 3. It is used to detect the state of the open phase and the sequence of the phase. 4. The sequence of the phase is indicated by a light emitting diode (LED) and a buzzer. Instruction: 1. LED for open phase check: Three orange LEDs indicate U phase, V phase and W phase respectively. 2. LED for phase sequence check: one red LED and one green LED respectively 3. Draw strap: put it on the wrist to prevent the instrument from slipping off the hand. 4. Test lead: red corresponds to U (R) phase (L1, R); Yellow corresponds to V (Y) phase (L2, S); Green corresponds to W (B) phase (L3, T) Notice: Actual color may be slightly different from the image due to different monitor and light effect. Please allow 1-3cm deviation due to manual measurement. Description: Working voltage: 60~600V (three-phase alternating current) Maximum withstand voltage: 2000V/min (pulse voltage 4000V) Measurable frequency range: 20Hz~400Hz Continuous use time: no more than 60 minutes at 200V ACV, no more than 4 minutes at 600V ACV Meter size: 85X64X23mm (not including test lead) Weight: about 200g includes: 1 set of Phase Tester