This long-wave medium-wave, high-frequency amplifier can be used in colleges, research institutes and radio lovers. That is input about 0dBm(1mW) output 50W - 4 Input and output impedance 50 ohm - 5 Input and output connector SMA female headï¼? Usually it cost about 35USD-50USD. If you receive defective item, please kindly notify us within 14 days.