2.1 SD speakerSpeaker for cellphone, laptops, ipod, mp3 Enjoy music anytime Built-in amplifier ... speaker with bult-in recharge battery specification:Good for use on outside activity. eg: Square, Yoga ... outdoors and ect.. with lithium and usb cable for power. you can choose as your requirments. Can ... with pure, vivid, distinct sound Compatible with laptops, iPod, MP3, MP4, MP5, cell phones, PSPs and ...