ACT pressure plates feature a special, single diaphragm design to dramatically increase clamp load without the adverse effects of double-diaphragm type clutches. Effective diaphragm designs are used to increase clamp load, reduce deflection and maximize clutch life. All diaphragms endure an exclusive four stage, heat treating process for unparalleled performance. The MaXX Extreme pressure plate provides a clamp load increase of 70-150% higher than stock and is recommended for race applications only as it makes the pedal feel very stiff and would be uncomfortable in street driving. In addition, all meet SFI Spec 1.1to ensure safety.