AIM VP95 IV Performance clutch spring for '98+ modelsVP95 IV is recommended for high performance engines producing 130 195ft lb of torque! (Dependent on diaphragm pressure rate. See chart here) For Harley Davidson '98 to '17 Big Twin models with 6 Studs Style Clutch and Diaphragm Spring. (except '13 and later Big Twin Model with A&S Clutch, 3 Studs Style) Click here for the fitment chart. 40% more clamping force at High RPM. (Clutch pull becomes heavier as RPM increases.) 15 minute installation. Install