Power Bank, Shinngo 4000mAh Portable Charger Ultra Slim Dual USB External Battery Pack for iPhone, iPad, Samsung, MP3, Tablets and More Silver ULTRA SLIM EXTERNAL BATTERY: Measure less than 10 mm thin, only weigh 4.23oz, the same thickness as your cell phone, allowing your easy grasp and purse storage. Simply connect your phone via Micro USB and enjoy uninterrupted power on the go. UNIBODY AVIATION ALUMINUM POWER BANK: Made of unibody aluminum brushed housing with premium craftsmanship, offering a sleek but durable feeling. Its brushed exterior can effectively resist scratches and fingerprints. COMPACT BUT POWERFUL PORTABLE CHARGER: Upgraded from the previous version, it is now equipped with dual USB ports: 2.1A smart-charging output and 1.0A output. It can auto-detect your device to deliver its fastest possible charge speed up to 2.1A. PROTECTION GUARANTEE: Built-in Premium Grade A Li-Polymer cell and premium microchips, which are safe and stable. It will automatically shut down if a short circuit or overload output occurred while the unit is charging. Built-in 4 LED indicators help to better identify the battery level and charging status. WHAT YOU GET: Shinngo 4000mAh Portable Charger, Micro USB Cable (30cm long, data sync and charging), User's Manual, 12-Month Warranty and 30-Day Money Back Guarantee.