Mounts directly to any Gold Mount on the camera for true perpetual, battery operation. Unlike "stacking" batteries one behind the other, electronics in the QR-HOTSWAP-GM allow for true "hot swapping" as either battery can be changed at any time. The circuitry automatically combines the output of both digital battery fuel gauges for accurate display in the cameras with the InterActive viewfinder features. Used with two DIONIC 90 or HC batteries, the lightweight (<13 oz/360g) QR-HOTSWAP-GM allows for a maximum 248 watt hours of capacity and seamless, truly perpetual power. QR-HOTSWAP-GM can be used with any combination of Anton/Bauer DIONIC 90, DIONIC HC, DIONIC HCX or HyTRON 50 batteries ONLY, due to the batteries’ sizes and weights.