XtremeMac InCharge Mobile for iPhone 3G_3GS (US) extends battery life for talk timeup to 4 hourslow-profile lightweight designfor ultimate protection easily convert from case withbattery to case without batteryoptions includes mini usb to usb cable forcharging and syncingled battery status indicators 8 hours video playback, 25 hours audio playback. Low-profile lightweight design for ultimate protection Easily convert from case with battery to case without battery options Includes mini usb to usb cable for charging and syncing 270 hours standby time