JP4 - HDG6 kit features ACT's highly regarded Heavy Duty pressure plate and spring - center 6 pad race disc delivering high torque capacity, aggressive engagement, quiet operation and increased toughness to withstand the demands of off - road racing. ACTs 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. ACTs spring center 6 pad race discs boast quality parts throughout, with robust spring center sections to absorb driveline shock and premium ceramic friction materials to hold power even under the most abusive conditions.