Cool Design Portable ABS Material 1900mAh High Capacity External Charger and Holder for Apple iPhone 4 Black Color ABS Material Holder. Cool Design Gives A Secure and Comfortable Grip on Foot and Makes Sure That Your iPhone 4 Never Look Out of Date. Easy To Use. It Fully Charges The Phone With A Single USB Cable. Just Charge It By Connecting The iPhone 4 Charger with Your PC Using The Included USB Cable. With the High Capacity 1900mAh/3.7V Battery, Enjoy Your iPhone 4 Without Worrying About Battery Level. LED Indication for Charging and Battery Level. Charging Built-in Battery Via USB Cable: 4-6 Hours. Rated Input: Mini USB 5V/0.7A. Rated Output: USB 5V/700mAh. Dimensions(L x W x D):5.5 x 3.93 x 0.78 inch.