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/5.51X3.54inWeight:400g/0.88lbMaterial: PlasticMaximum Current Consumption: 400maMaximum Working Power: 100wMaximum Possible Measured Power: 150wMinimum Power Required To Start Tuning: 5wMinimum Possible Measured Power: 0.1wMeasurement Steps With Power Up To 10w: 0.1wMeasurement Steps With Power Higher Than 10w: 1wPower Measurement Accuracy: 10%Maximum Installed Inductance: 8.53uhMinimum Installation Inductance Step: 0.05uhMaximum Installed Capacitance: 1869pfMinimum Installation Capacitance Step: 10pfNumber 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.