The circuitry automatically combines the output of both Digital battery fuel gauges for accurate display in the cameras with InterActive viewfinder features. Used with two Dionic 90 batteries, the lightweight QR-Hotswap allows for 180 watt hours of capacity and seamless, truly perpetual, power. QR-Hotswap can be used with any combination of Anton/Bauer Dionic 90 or HyTron 50 batteries ONLY. QR-Hotswap comes in three mounting options.