Specification :

Built-in High quality amplifier
Thin and simple design
Recharge and playback for iPhone
AC adaptor included
Battery powered( 4 AA size or rechargeable, not included)
Powerful and Crystal sound qaulity from 2pcs of 2.25inch driver unit
Bass booster function
3.5mm Aux jack for connection to other MP3, CD, Laptop…
Output power: 4Wx2
With a frequency switch for frequency change