Eco 12540 ECO 1900mAh Power Case for Apple iPhone 4 & 4S - Retail Packaging - Black Includes Micro USB Charging Cable Protection: Short Circuit/Overcharge Capacity: 1900mAh, Input: 5V, Output: 5V Access to All Buttons & Features, Charging & Data Syncing Capabilities Lightweight & Durable Design, Extends Battery Life, LED Battery Indicators