Steel Back Heavy Duty Street System, 70% over stock holding capacity The FX100 System uses the Power Plus I Pressure Plate with the Steel Back organic disc. This clutch is engineered for heavy-duty street use. It is specifically designed for extended wear and additional clamping force for the enthusiast who has added an exhaust system, an intake system, up to 50hp NO2 upgrade, or other non-forced induction external bolt-ons. As with most Clutch Masters clutches, the FX100 incorporates the Hi-Leverage pressure plate design and the steel back disc. It features only slightly increased pedal pressure (over stock components), longer life than stock, and normal clutch feel during engagement and disengagement for a very smooth operation.