Imprint Method: UNIMPRINTED - The Bolt Aluminum 2,200 mAh Power Bank is a rechargeable lithium ion Grade A battery that's powerful enough to charge smartphones, MP3 players and more. The reusable power bank charges via USB cable (included) which can recharge the battery backup or be used to charge devices with a micro-USB input like Android smartphones from Samsung®, Motorola®, HTC®, Nokia®, and others. Green LED indicator light illuminates when device is fully charged. Input: 5V/500mA. Output: 5V/1000mA.