... , self test 3.85dB high sensitivity 4.8digits LED display Digital Frequency Meter,HC-F1000L, frequency from 10Hz~1GHz,digital display Model F1000CFrequency measurementsChannel ARange 1Hz ... Better than ± 2x10-6 / dayOutput “0” level: 0V~0.8V “1” level: 3V~5VGeneral Display 8 digit 7mm red LED display with decimal point,gate, overflow ...