Camson 1900 mAh External Rechargable Battery Case For iPhone 4 And 4S (Black) This Piano finished glossy Black case is solid built, Elegant Designed and snuggly fit the iPhone 4/4S. With the included 1 year battery case exchange warranty, you purchase for beloved iPhone 4/4S can not be more secure than ever. Internet Use:Up to 6 hours on 3G/Up to 8 hours on Wi-Fi Audio Playback: 30 hours Video Playback: 8 Hours Fully Enclosed Rubberized Dura-Body allows access to all ports and functionalities On/Off function lets you decide when to use the extra power boost and 4 LED indicator lights show battery power level On/Off function lets you decide when to use the extra power boost and 4 LED indicator lights show battery power leve High Capacity 1900mAh Internal Lithium Polymer battery provides hours of extended use and protection Charging Time: 4 Hours Output Voltage:5V Output Current:500mA Input Voltage