2.1 SD speakerSpeaker for cellphone, laptops, ipod, mp3 Enjoy music anytime Built-in amplifier with pure, vivid, ... . eg: Square, Yoga outdoors and ect.. with lithium and usb cable for power. you can choose as your requirments. Can be ... -in amplifier with pure, vivid, distinct sound Compatible with laptops, iPod, MP3, MP4, MP5, cell phones, PSPs and more Power rating ...