The Canon BG-E8 Battery Grip for the EOS Digital Rebel T2i (EOS-550D) SLR camera holds up to 2 LP-E8 battery packs simultaneously to effectively double your shooting power, plus the grip includes a holder to use 6 AA batteries. In addition, the grip includes a vertical shutter release and a mode wheel to provide access to all of the camera functions and make shooting with the camera in a vertical position just as comfortable as shooting horizontally.