The 500 Series Is a great High Performance Disc In The Single Disc Platform. Suited For Both Street And Strip Duty, The 500 Series Will Give You Both The Smooth Engagement And Holding Power You Need To Get The Job Done. This Disc Has A Segmented Semi Metallic Ceramic Facing On the flywheel side and a full face orgainc on the pressure plate side for a smooth engagement. Mcleod Racing Offer Various Input Shaft Splines For All The Popular Vehicles In 9-11/16", 10.5",11" & 12" Disc Diameters.