The Zacuto C300 Grip Handle Relocator attaches to a separately-sold Zacuto Zgrip to achieve distance-extended, chest-level handling of a Canon C300 Grip (which is a button-equipped hand controller that comes with the C300).
The separately-sold Zgrip is an upside-down V, with each side of the V a 15mm rod. The V connects to the front of a full Zacuto rig to serve as handle-bars for the rig, and the Relocator connects to one end of the V to serve as a handle (and as a base for the C300 Grip).
So what then is the Relocator? The C300 Grip, the C300-provided Controller, attaches onto the side of the Relocator, and a 24" cable that's already built into the Relocator snakes up a rod of the V to connect to the C300. The Relocator thus provides two purposes: it allows the C300 Grip to be used on a Zgrip, and allows it to be used from 24" farther than usual. (The C300 Grip's native cable connects into the Relocator.)
Since the rods of the V are long enough to reach chest level (as opposed to shoulder level), you'll be able to use the Relocator and thus the C300 Grip at chest level. The Relocator is fully articulating until locked in by lever.
Attaches to a Zacuto Zgrip to give you distance-extended / chest-level use of a Canon C300 Grip