Plates Clutch Lock Up BtLow Profile Lock Up Pressure Plate Conversion KitSpecifically designed to fit under the stock or aftermarket primary derby covers and increase the capacity of your stock clutch by using stainless steel weighted arms that progressively increase pressure to the clutch as rpm increases This also allows lever effort to be kept to a minimum even with big inch motors Three different sets of six coil springs (light, medium, heavy) are included for a variety