SmallRig Dummy Battery EN-EL15 3247 is an accessory designed to complete power supply system and provide users with easy and quick access to the external power supply to extend shooting time and focus on video creation; it has a total length of 600mm and delivers stable 7.4V output through the 5.5 / 2.1mm DC output port. It can be easily and quickly installed in the camera battery door and used for a continuous and stable power supply for the Nikon camera.