This is the world's thinnest iPhone 4 case with battery charger that nearly doubles the life of your battery. Say goodbye to chunky and clumpy additions to your iPhone that can make it almost impossible for it to fit in your back pocket. With the Power Sping's sleek form fitting design we are extremely confident you will love this product.
• The worldwide highest capacity external battery for iPhone 4.
• Product Dimension: 124 x 65 x 18 mm.
• Technical Specifications: Input: DC 5V/500mA, Capacity: 1600mAh.
• Standby time: Up to 360 hours. Talk time: Up to 6 hours on 3G, Up to 13.3 hours on 2G. Internet Use: Up to 6 hours on 3G, Up to 10.6 hours on Wi-Fi. Audio play: Up to 36 hours. Video play: Up to 10.6 hours.
• Package Contents: MiLi Power Spring 4, Mini USB cable, User's Manual.