The EH-73P from Nikon is a charging AC adapter for select Z, COOLPIX, and KeyMission cameras. It facilitates charging a camera’s battery while it is inside the camera, and requires the additional UC-E21 USB Cable for connecting to a camera.
It has millivoltage input capacity of 100v-240v 50/60Hz for worldwide operation. The EH-73P is supplied with select compatible devices and is sold here as a spare or replacement accessory.
Nikon EH-73P Charging AC Adapter Camera Compatibility