It comes with built in 400 mAh battery. Assorted colors is available that meets different interests. It works by connecting cell phone and tablet using the Bluetooth that is great giveaways for any events, office meeting giveaway, sale meeting, etc.
2.2 X 2.2 X 1.7
PriceIncludeClr: 1 color
PriceIncludeSide: 1 side
PriceIncludeLoc: 1 location
DecorationMethod: Screen printed