Check the listing for details. Accuracy Hz LED Display Tester Voltmeter Frequency Meter for Household. Condition: New. Listed at 8.88 USD. Accuracy Hz LED Display Tester Voltmeter Frequency Meter for Household Features: Frequency Meter 50-500V LED display of and frequency in the same for time. Frequency The data is more intuitive, LED two-color display, + green, clear and easy for at a glance. This Frequency Meter is easy to install, embedded installation, more stable. Meter only fits with 50-60HZ power supply, not be used for square inverter output. Specifications: Size: 70x40x25mm/2.7x1.6x1.0in Measuring Power supply: 2 wires AC50-500V Package Includes: 1X Frequency Meter note: Please allow 1-3cm error due to manual measurement. pls make sure you do not mind before you bid. Due to the difference between different monitors, the picture may not reflect the actual color of the item.