The PowerTap Multi is an accessory adaptor. Four female PowerTap receptacles expand from any Gold Mount PowerTap to accomodate 4 separate devices. Perfect for powering multiple wireless receivers as well as an Ultralight-2 from a single camera battery (10 amps max).
I picked this up for the sake of powering an on-camera monitor and a DSLR from the same V-mount camera battery. It, my plan, didn't work as the battery is too high a voltage to work with my LP-E6 dummy. No fault of this product. Even though it was expensive I'll keep it for future use....
It's a bit pricey, but the cable is the perfect length, and the build is solid. I look forward to many happy years together with this absolute lifesaver.