EPCTEKGreen Lovely 8400mAh USB Port External Charger Portable Power Bank Battery for Mobile Phone Droid, Google Glass, Nexus 4, Nexus 7, Nexus 10 High Capacity, 8400mAh;Fit for your iPhone 4S / 4G / 3GS/Samsung Galaxy S4 / S3, Nokia and other smart phones; Compact, portable, Sleek, stylish and compact design; Easily fits into your bag to provide instant power; Perfect for trainroad trips, or whenever you need to charge your mobile devices wherever you are. High quality Lithium-ion battery ensures reliability; Input: DC 5V-1000mAh,Output: DC 5V-1000mAh; Charge the power bank via standard USB or AC adapter (not included).