... 4,Mini size,Easy to take 5.FM Radio,MCU system V-5 Audio mini voice portable ... amplifier with USB/TF and FM radio Features*Mini size,easy to take*18W output power ... by TF Card, USB flash disk supported, FM Radio Function*Built-in 2pcs 3.7V/1100mAh Lithium Battery, ... x 1pc Applications Teaching, Tour guiding, Morning exercise, Training, Sports, Speech,Publication,Outdoor entertainment