ZAGG ZSPARQ3100SLV 3100 Silver Battery - Retail Packaging - Silver/Black 3,100 mAh Lithium Polymer Battery - Has the power to charge an iPhone two times 5 LED lights indicate power level, 20%-40%-60%-80%-100% Ideal for medium-to-heavy electronics users who need to keep their phones or tablets powered 1 USB Port with 2.1A output Physical Size 4 x 2.75 x 1 inches - Weight .33 lbs