1. Small and portable, powered by RF tap power supply, easy to carry, very suitable for radio amateurs to use in the field. 2. It can be used to measure radio frequency signals. It uses 5 LEDs to indicate signal strength and different colors for different SWR ranges. 3. It is used to test the signal-to-noise ratio of shortwave radio signals in the frequency range of 3-30MHz. The input power does not exceed 100W, and the minimum LED (1.0 corresponds to green light) requires 5W power. It is suitable for various shortwave radio equipment. 4. This equipment is commonly used in radio communication systems such as radio broadcasting, television broadcasting, and radio communication. 5. It helps the operator to determine the signal strength, thereby adjusting the settings of the radio equipment to improve signal quality and reliability. There are no components that need to be adjusted in the entire circuit, and it will 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 shortwave range without any calibration and adjustment, which is very simple and convenient for DIY enthusiasts. Name: SWR Meter Usage Frequency: 3-30MHz Highest Power: 100W Maximum Insertion Loss: Less than 0.3dB Standing Wave Ratio: Less than 1.2 Interface: M Female Due to different batches, there may be differences in product appearance, color, and printed text, which does not affect the use. Color: 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 to be slightly different from the real thing. The measurement allowed error is +/- 1-3cm.