ZM1-HDG4 1990-1993 Mazda Miata ACT HD 4-Puck Sprung Hub Clutch Kit includes a pressure plate, clutch disc, release bearing, alignment tool, and pilot bearing. HD Pressure Plate:Clamping loads increase 20% - 50%. Pedal effort feels stock to moderate. SFI certified to ensure safety. G4 Spring Centered 4-Pad Disc:Recommended for road racing. Track geared disc that will hold up to track abuse and be tame enough for the street, perfect for non-daily driver lightweight autocross and time trial cars that are driven to the track. Benefits are: increased torque capacity and spline life over a solid disc, lower inertia, faster shifts, quiet operation, reduced driveline shock, and sharper engagement than stock type or 6-pad disc.