1. The LED AC voltage frequency measuring instrument is mainly used for real-time measurement of the AC voltage frequency in the electrical circuit, and uses the LED digital tube display to display in digital direct reading mode. 3. NO EXTRA INDIVIDUAL POWER SUPPLY: Voltage frequency meter can directly connect two wires to the tested voltage to measure voltage and frequency without power supply. 2. WIDE MEASURING RANGE: Digital AC voltmeter frequency meter can measure voltage of AC 50~500V, frequency 10.0-99.9hz, accuracy is 1% ± 2 digits, with high working efficiency of 2 times/s measuring speed. 4. SUPER SMALL SIZE: With 68x68MM hole size. This voltage frequency meter can be installed on anywhere flexibly, compact and convenient. 5. CLEAR AND INTUITIVE DISPLAY: Voltage frequency tester uses a 0.56in LED font size to display the distribution of data in a concise form, so that can quickly understand the data., Weight: 0.15652820602 pounds, Manufacturer: NONDK