Brand: Advanced Clutch TechnologyManufacturer's Part Number: ZX4-HDR4Part Type: Clutch KitsProduct Line: ACT Heavy-Duty Clutch KitsAutomotive Fittings Part Number: ACL-ZX4-HDR4UPC: 00842385014346Clutch Usage: PerformanceClutch Disc Quantity: 1Flywheel Included: YesInput Spline Quantity: 23Input Shaft Diameter: 1.000 in.Disc Diameter (in.): 9.449 in.Disc Diameter (mm): 240mmDisc Material: CeramicDisc Style: 4-paddleHub Style: SolidPressure Plate Style: DiaphragmThrowout Bearing Included: YesAlignment Tool Included: YesPilot Bushing Included: YesPilot Bushing Material: Steel roller bearingFlywheel Material: Billet steelEngine Balance: InternalCounterweight Assist: NoMounting Hardware Included: YesQuantity: Sold as a kit.Description:ACT heavy-duty clutch kits offer a clamp load increase of 20 to 50 percent over OEM, significantly increasing torque capacity. The pedal feel with these clutches varies from stock to a moderate increase. Available for street and race applications, many are SFI-certified to ensure safety.