... design rechargeable trolley speaker Wireless pa system with USB/FM radio/wheels/handle,trolly speaker Model:NDP-210Distortion: 0.1% Specification ... SD memory card function, Support MP3 music format2. With FM Radio, Guitar input3. With Karaoke function,2 microphone socket input4. Volume ... and other audio input Wireless pa system with USB/FM radio/wheels/handle,trolly speaker