TA1-HDR4 kit features ACT's highly regarded Heavy Duty pressure plate and rigid 4 pad race disc delivering high torque capacity aggressive engagement and increased toughness to withstand the demands of off-road racing. ACT’s exclusive diaphragm design increases clamp load reduces deflection and maximizes clutch life. All diaphragms endure a four-stage heat-treating process for unparalleled performance. ACT precision pressure plate cover stampings provide rigidity and consistency while precision machined pressure plate castings absorb heat. ACT’s rigid center 4 pad race discs have a virtually indestructible rigid center and premium ceramic friction materials to hold power even under the most abusive conditions. Rigid design eliminates torsional damping for simplicity reduced weight and quicker shifting.