I can't find a picture online, but it's a factory option (85R) for the interceptor utilities that attaches to the rear of the console and runs to underneath the rear seat on the transmission hump. It's a great feature the allows much shorter wire runs and shortens build times.
I have built a PIU with running wires down the sills. It sucked and theres very little room to work with and all the wiring runs are twice as long as the ones without. I have a build where I thought it'd be easy to find the part number and purchase the oem wire conduit. But that has not been the case.
Anyways, it's an awesome feature. I can build a similar one, but was hoping to just purchase the real one instead, to save time.