iRulu 2600mAh Cylindrical Tubes External Battery Traveling Mobile Power Bank For Iphone 4 / 4s, 3gs/3g, Ipod, Samsung Galaxy,other Digital Devices,Black LED indicator light show, at any time control power Long service life,more than 500 times the charging and discharging NO AC adapter is included. The Battery Pack is compatible with USB chargers come with your Cell phone or tablets. Rechargeable: Convenient rechargeable battery allowing you to always have a battery charging backup when you are away from a AC outlet Slim, Sleek, Compact, portable and stylish Design.