AD22-DFM Digital Frequency/Current/Voltage Meter designed on the base of AD22 LED LED Indicators in this field. It can be used in the Panel Board to showing the rated frequency in the circuit. The AD22-DFM Digital Frequency/Current/Voltage Meter Indicator also can be used to instead of the traditional Panel Meter. This Indicator with the advantage of compact design. It can be easily installed on the panel board.