The MB-N12 is a dust- and drip-resistant battery grip that can be used for vertical shooting, as well as to increase shooting time versus using the camera battery alone. It’s also a great way to counterbalance the weight of telephoto lenses.
Controls for vertical shooting include a shutter-release button, main and sub command dials, AF-ON button, sub selector, and Fn buttons. You get up to 1.8x more operating time with two EN-EL15c batteries in the grip and can hot-swap batteries when needed. Plus, a USB-C port on the grip lets you charge two batteries sequentially when the grip is not attached to the camera: perfect for overnight charging.