The AD-PS2 is a supplementary power source for your photographic equipment. It converts a V-Mount battery into a universal power bank. The dual bridge plate at the back makes it a perfect counter weight in combination with a power source while shooting with your DSLR rig. The DR-E5 coupler makes it possible to connect your camera to a direct power supply. You replace the loose battery for the DR-E5 coupler and you can use your camera without worrying about running out of battery.