JAPANESE OEM QUALITY? JAPANESE OEM DESIGN?? Manufactured from Japanese SUS 420 Stainless Steel? Heat treated to HRC 36+-2 standards? Precision CNC machined and laser cut technology A full OEM replacement disc – constructed from two segments of stainless steel which are rivetted together with bobbins to allow the braking surface of the disc to expand under the extreme temperatures of braking. Lightening and drill holes are then applied to match the OEM design and further improve braking performance and reduce the disc temperature.