Imprint Method: Laser - Engraving, Imprint Method: Color Print Pad - Pad Print - The Sleek Aluminum 4,000 mAh Power Bank has a rechargeable lithium polymer Grade A battery (14.8Wh) with enough power to charge smartphones, MP3 players and tablets with a total output of 5V/2A. The dual output lets you charge two devices simultaneously. It also includes a battery check button to ensure that you know how much battery life is left. The reusable power bank charges via USB cable (included), which can recharge the battery backup or other devices with a micro-USB input, like Android™ smartphones from Samsung®, Motorola®, HTC®, Nokia® and others. Input: 5V/1000mA. Output 1:5V/2000mA; Output 2:5V/1000mA. Power banks are permitted in carry-on luggage only, and at the discretion of TSA agents.