... size,travel,sports,recreation.3.Uses D kind of digital power amplifier chip,low powerloss,high efficiency.4.Uses 40mm the neodymium ... built-in lithium ion battery+outside sets at the power source adapter. Specification:Power output:3W*2(RMS)RF 100Hz-20KHz S ... /N ratio:≥80dB Impedance:4 Power:DC 5V Payment:TT,western union,paypal,money gram,cash ...