The Vivitar Battery Grip for Sony A9/A7RIII/A7MIII Cameras uses 2 NP-FZ100 batteries which provides the power to shoot up to 800 pictures. Mounted on the bottom of the camera, the grip sports a vertical shutter button just perfect for portrait photography and includes an AE/AF lock button and zoom control for consistently great shots. Specifications Mount: Bottom mount Compatible with Sony A9/A7IIIColor: Black Features AE/AF button Zoom in/out button Vertical shutter button for portrait photography Uses 2 NP-FZ100 batteries(not included)