It’s the Phase Contabulator. It connects under the plastic to the Dingle arm which runs in sync with warp modulation device.
Oh man Mellow Joe is screwed. He lives in Texas & has been riding Yamaha’s for the last few years. Wait til he try’s adjusting the Quantum flux inhibitors on that new RT.You have to have the quantum torsion stabilizer to use this set up. I learned the hard way; part of me is still in Arizona.