This is a one-piece big rotor rear kit that can be used as a genuine replacement.
This big rotor has been enlarged by 70mm from the original size of 260mm to 330mm.
This part uses a 330mm wide big rotor to significantly improve the braking force, controllability, life cycle, etc. of the brakes, and is designed specifically for each vehicle model and can be installed with a bolt-on. This is a special part for updating time attacks, especially recommended for circuit driving users. In FF cars, the front is burdened by the three elements of stopping, turning, and accelerating, so the behavior of the rear is greatly affected. This big rotor is one of the important elements for under-countermeasures in the setting of the rear suspension and the braking force of the rear brakes. To install, attach a special bracket and move the caliper to match the big rotor. It can be installed without any processing other than removing the splash guard.
It is introduced on Ameblo's "M&M HONDA's Honda Honki."
https://ameblo.jp/mandm-honda/entry-12243287430.html