The Sony VG-C1EM Battery Grip attaches to the Sony Alpha a7, a7R or a7S cameras and extends (with one battery) or doubles (with two batteries) your shooting time. This rental comes with one battery and you can use the in-camera battery as your second. The grip allows the camera to use up one battery at a time and spares can be replaced without turning off the camera (handy for videographers). The grip can also improve shooting ergonomics, as the shooting dials are repeated on the grip for a more natural position when shooting vertically (handy for portrait photographers). The grip is ideal for Sony a7 shooters who are going to be out in the field and away from power sources for extended periods.