Designed specifically to fit under stock or aftermarket primary/derby covers Increases the capacity of your stock clutch and keeps lever effort to a minimum even with big inch motors Stainless steel weighted arms progressively increase pressure to the clutch as RPM's increase Three different sets of six coil springs (light, medium, heavy) are included for a wide variety of spring pressure options The coil spring design provides smoother shifting and a more linear engagement compared to a diaphragm type spring Easy bolt-on installation No modifications required Simply replaces the OEM pressure plate/diaphragm spring assembly Whether you're looking for a lighter clutch effort for a stock Big Twin or serious no-slip performance for a big motor, the Barnett Performance Products Low Profile Lock-up Pressure Plate has got you covered CNC precision machined black anodize billet aluminum pressure plate Polished aluminum lock-up head Chrome torx derby cover fasteners included Coil springs are made from chrome silicon, heat-treated and 'pre-set' Attractive high-end design looks great with clear aftermarket derby covers