Portable, compact and simplicity. Sealed design and very convenient to use. Non-slip and comfortable grip design. One LED charge status indicator light. Custom fit for the contour of iPhone 4G precisely. Designed for use on the go or in an emergency. Prevent your iPhone 4G from scratches and dust. Used for charging your iPhone 4G anytime and anywhere. Extend the working time of your cell phone. Built-in 2000mAh lithium battery. One switch on/off button for easy operation. Come with a foldable stand for supporting your iPhone easily. Compatible with iPhone 4G. Battery type: lithium-ion battery. Capacity: 2000mAh. Standby time: up to 390 hours. Talk time: up to 6.5 hours on 4G. Input voltage: DC 5V. Output voltage: DC 5V.