USB SD Speaker, 1.USB , LINE IN, TWO POWER SUPPLY(USB+4xAAA BATTERIES) LI-ION. 2.Competitive price&High quality USD SD SPEAKER 1.Abundant supply and prompt delivery.2.Easy to handle, built-in BTL stereo amplifier, compatible with different audio device such as laptop, mobile phone,ipod ,MP3,MP4 and CD.Especially designed driver unit ,with beautiful sound.3.Using computer USB port instead of power ...