Feature:Operating voltage: 9VTest frequency range: Within 500mhz get high precision, more than 500mhz test results for reference only!Test frequency type: RF radio frequency, such as walkie-talkie and other wireless devices. At the same time can also be measured cable frequency!How to use: Power on to test. Board comes with adjustment capacitor, you can manually calibrate!Specification:Input signal amplitude: 0.5-5VInput impedance: 20-200 ohmsBest impedance: 50 ohmsNote:1, Can not use more than 9v voltage for power!2, The test frequency is wide, and this product don't comes with gain antenna, you can DIY antenna gain, can effectively increase the test range!3, If you do not know how to make antenna, a wire is also possible.Package includes:1 x 9V Frequency MeterTest pictures, for reference only: