re-engineered the disc to strengthen the spring retainer plate (thicker material) so that it would not come apart under high RPM. The disc they were using was a Nissan disc. They designed their own to go with the pressureplate in a very short time after the failure of my disc and that, to me, says a whole lot. In addition to that, they sent me a new disc free of charge and very quickly too. I can't say anything but good words about RPS and Greg D.