Exclusively designed for the PENTAX K-7 camera body, the Battery Grip D-BG4 is powered by either a rechargeable lithium-ion battery or six AA-size batteries. Since it supplements the camera’s battery as an additional power source, the number of recordable images is greatly increased. To facilitate vertical-position shooting, this grip features extra shutter-release button, preview lever, electronic dials, AE-lock button, Green button and AF button. It also provides the same dustproof, weather and cold-resistant construction as the camera body itself.