Never miss a call and a message again with the premium standby batteryDo you know， the mobile phone battery with the excellent battery life will bring conveniences to your life. This is external backup battery case designed for apple iPhone. The portable battery case increases the working time of apple iPhone. It has great hand feeling with the use of non-slippery material. All function buttons and ports are accessible without removing the cover， simple and convenient. It can not only work as a good protective case， but also as a portable external backup battery. It is a must have gadgets when you travel. This unique case is waving to you， come to have a try                                    Features            Extends up to 30 hours usage while charging the internal batteryLight-weight， super-slim design to carry with your iPhone or iPod Conveniently charged via any USB portsHigh-capacity， rechargeable lithium-ion batteryLED indicator for battery power levelNo memory effect， Li-ion battery built-in                                                            Specifications            Battery type    Lithium-ion Batterty    <br>Capacity    1900mAh    <br>Input    5V 800mA    <br>Output    5V 500mA Max    <br>Charge time    4 Hours    <br>Dimension    12.5 x 6.6 x 2cm / (4.92 x 2.6 x 0.79)" (mm)    <br>Weight    144g / 5.08oz    <br>Material    Metal / Plastic    <br>Compatible with    iPhone 4 / 4S    <br>                                                            Package Includes            1 x 1900mAh Rechargeable External Battery Case with USB Cable for iPhone 4/4S Black