1. Small and , powered by tap power supply, , easy to carry, very suitable for amateur radio enthusiasts to use in . 2. It can be used to measure radio frequency signals. It uses 5 LEDs to the strength of the signal and LEDs of different colors to different SWR ranges. 3. It is used to test the signal-to-noise ratio of shortwave radio signals in the frequency range 3-30MHz. The input power does not exceed 100W, and the smallest LED ( 1.0 corresponds to green light) requires 5W power. It is suitable for various shortwave radio equipment. 4. This equipment is usually used in radio communication systems such as radio broadcasting, television broadcasting, and radio communications. 5. It helps the operator determine the strength of the signal and thereby adjust the settings of the radio equipment to improve the quality and reliability of the signal. There are no components that need to be adjusted in the entire circuit, and it work normally as long as the connections are correct. IN is the radio frequency input and OUT is the radio frequency output. The IN terminal is connected to the radio frequency ANT, and the OUT terminal is connected to the antenna. It can be used in the short wave range without any calibration and adjustment, which is very simple and convenient for DIY enthusiasts. Name:SWR meter Frequency of use:3-30mhz Maximum power:no more than 100W Insertion loss:Less than 0.3dB Very short wave:Less than 1.2 Interface:M female Due to different batches, there may be differences in product appearance, color, and printed text, which not affect the use. Colour:Black Material:Metal Size:25x25x50mm/0.98x0.98x1.97in (excluding M base) Package Contents: 1 * SWR Meter Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.