Specification:

Signal and noise ratio of power amplifier: ≥68d
Input sensitivity :AUX 450mV FM 380mV SD/USB 450m
Loud speaker:1.77 inches (external diameter 45mm
Magnetic resistant:4Ohms 5
Power supply : DC 5
Battery:External battery 600m
Size: 180mm*80mm*110m
AC power adapter , computer USB power rotate connect line(can choose)
Output :RMS 6W (3W+3W)
Description:

You can play directly to SD / MMC card, U disk, MP3 format audio file. Does not need to be switched automatically read, remember. Enjoy music mobile andpowerful multimedia sound box, perfect for listening to your mobile phone music player, support MP3, MP4, laptop, PC.
Designed for music mobile phone and notebook computer3.5mm interface connector, also apply to the MP3/ 4, PC
without consumption of electric quantity of the mobile phone, portable rechargeable lithium battery, is a professional portable mobile phone music equipment. Built in rechargeable lithium batteries can work 3 hours charge time, by 4--5hour.

Fine workmanship, , feel good, very good product.