Power Pack Iphone 4 rechargeable Battery Case-Li Polymer Battery Lithium-ion 1900mAh Black Ultra Slim Exteneded Battery pack Protector Case for Iphone 4 Stand By time: Up to 230 Hrs and Cell Type:Li Polymer Battery Lithium-ion 1900mAh Up to 8 hrs on WiFi and Audio Up to 30 hrs and Video playback up to 8 hrs On and Off button switch 4 Level LED battery indicator