Greg did R&D with RPS to make sure that it could handle the abuse from cars requiring upgraded clutches (further details from there will have to be had from Greg himself). The lightened aluminium segmented flywheel is also made by RPS for SZ as well. The SZ emblem is cut into both the clutch and flywheel. I believe that only a couple have been sold to this point as I don't think Greg has put it on their site yet (but I could be wrong, wouldn't be the first time).