Includes Monoloc P/PL-M Heavy Duty Light to moderate pedal effort, confidence during hard shifts, positive engagement; Available life extended by ACT's exclusive diaphragm design, dramatic improvement in release mechanism life; Carefully engineered for improved durability, precisely assembled, accurately balanced, major improvement in release mechanism; Recommended for street and race use; 100% clamp load tested and dynamically computer balanced for smooth high RPM reliability, includes ACT's patented Monoloc SB018 is an ACT pressure plate that uses 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. ACT's Heavy Duty pressure plates increase clamp load by 20 to 50 percent. ACT's Heavy Duty pressure plates are recommended for use with a street or race disc. Monoloc is a one-piece, direct replacement or upgrade to the standard, two-piece wedge collar and wire ring featured in pull-type clutches. The spring tension of the segmented retaining ring is carefully calculated and tested for optimal performance. It provides uniform loading on the bearing and pressure plate to assure proper alignment, regardless of driver influence or vehicle modifications. Monoloc's hardened chrome-moly steel construction will provide years of service.