"Excellence in Performance", backed by the best one-year warranty in the industry! XT/Perf Street Rigid Moderate to heavy pedal effort, smooth positive engagement, increased gear rattle; Longer clutch life achieved through ACT's exclusive diaphragm design, rigid design may increase spline wear; Precisely balanced and uses premium organic friction materials for heat tolerance, faster recovery from overheating and prevents warping of mating surfaces; Recommended for street and race use; 100% clamp load tested and dynamically computer balanced for smooth high RPM reliability MB1-XTSD kit features an Xtreme pressure plate for the most demanding driver. ACT Xtreme pressure plates use exclusive diaphragm design to increase clamp load, reduce deflection and maximize clutch life. All diaphragms endure a four-stage, heat-treating process for unparalleled performance. ACT pressure plates have precision cover stampings to provide rigidity and consistency. The ACT Performance street rigid-hub discs feature premium organic materials with high copper content for better heat transfer and steel-backed lining for greater burst strength and durability. The chrome-moly hub is heat-treated for strength and durability. Rivet design and materials are carefully selected for maximum strength. These discs are the minimum weight street disc for faster shifts. ACT's Street rigid-hub discs provide race-proven performance with street manageability.