"Case Relay Camera Power System (CPS) lets you power your camera continually with an external battery pack or wall power, providing peace of mind knowing you have an uninterrupted power source for your camera. Requires Relay Camera Coupler sold separately. More cost effective than purchasing multiple proprietary camera batteries Power sources are non-proprietary. Power your camera with the same 5V battery you use to charge phones or tablets. Never need to charge camera batteries again. And never run out power. Compatible with most Canon, Nikon, Sony, Panasonic, Fuji and Olympus cameras. Check to confirm your camera model is supported. A Relay Camera Coupler (sold separately) is required to use Case Relay External Power System. Manufacturer camera battery couplers require use of the included Relay Adapter Kit Power your camera with any 5V external battery pack or AC power source With Case Relay, you'll never run out of power and never need to stress about forgetting your camera batteries. If you're shooting and get low on battery power, simply swap out external batteries throughout your shoot. Case Relay's internal UPS battery will keep your camera powered while you exchange external batteries. Utilizing a wall outlet or external batteries, you could in theory shoot forever with consistent power flowing to your camera through Case Relay. How does it work? Simply insert the Relay Camera Coup"