Features: The device consists of a set of seven capacitors and seven inductors, which enables it (with the largest configuration) to work effectively in the broadband, 1.8-55 MHz amateur radio HF band. High quality plasric housing, stable and reliable performance, practical, easy to operate and use, has a long service life. The antenna tuner is automatically tuned without any control wires, suitable for most radio stations. Power supply voltage: USB charging or you can install battery in it. Automatic antenna tuner is assembled,no need install by yourself . Package Includes: 1 Mini Automatic Antenna Tuner Specifications: Size: 14.5X9cm/5.51X3.54in Weight:400g/0.88lb Material: Plastic Maximum Current Consumption: 400ma Maximum Working Power: 100w Maximum Possible Measured Power: 150w Minimum Power Required To Start Tuning: 5w Minimum Possible Measured Power: 0.1w Measurement Steps With Power Up To 10w: 0.1w Measurement Steps With Power Higher Than 10w: 1w Power Measurement Accuracy: 10% Maximum Installed Inductance: 8.53uh Minimum Installation Inductance Step: 0.05uh Maximum Installed Capacitance: 1869pf Minimum Installation Capacitance Step: 10pf Number Of Panel Buttons: Power Pow, Direct, Automatic, Function note: Due to the problems of lighting effects and shooting angles, there will be certain tolerances in the product, please understand. Please allow 0-1cm error due to the manual measurment.