The Precision BG-C1 is a battery grip designed for use specifically with the Canon EOS XS, XSi, and T1i digital SLR cameras. It accepts up to 2 LP-E5 batteries to effectively double the camera's battery life. The included AA battery holder allows you to use 6 AA batteries for added convenience. The BG-C1 offers an alternate shutter release button, aperture/exposure compensation button, AF point selection/magnify button, AE lock/FE lock/Index/reduce button, and main dial to facilitate shooting in a vertical orientation.