KETOTEK Digital AC Voltmeter Panel Mounting Meter AC80-300V Frequency Counter 45.0-65.0 HZ LED Display Voltage Frequency Meter Tester 2 in 1 meter which can measure AC Voltage and frequency simultaneously It is for testing AC 80V to 300V with high accuracy and high working efficiency of 2 times/s measuring speed It can directly connect two wires to the tested Voltage to measure Voltage and frequency without power supply Only suitable for Pure AC45-65hz Mains supply, It can't be used for measuring circuit of square wave, inverter output and sine wave LED high light display better than LCD