VP95 IV Part Number: VP026-95IV Fitment: For Harley Davidson '98 to '17 Big Twin models with 6 Studs Style Clutch and Diaphragm Spring. Click here for the fitment chart. (except '13 and later Big Twin Model with A&S Clutch, 3 Studs Style) Features: 40% more clamping force at High RPM. (Clutch pull becomes heavier as RPM increases.) 15 minute installation. Install through the derby cover without removing the primary cover. Fits behind the stock derby cover. Can be use with cable and hydraulic clutch controls. Diaphragm Spring reference with VP-95IV @4000rpm 280lbs = 130 ft-lbs torque 320lbs = 145 ft-lbs torque 340lbs = 150 ft-lbs torque 380lbs = 160 ft-lbs torque 480lbs = 195 ft-lbs torque Note: H-D stock derby cover, 103" and 110" CVO Covers (except any special or '03 anniversary) are not required a derby cover spacer. Non-stock derby cover (including any special or '03 anniversary cover) and 3 holes derby cover may require a derby cover spacer.The size of the displacement above is a just guideline to select VP clutch and spring. These numbers will be changed depend on motorcycle specifications. Patent#: US 7,516,825 & US 7,428,955 Installation Instructions Derby Cover Application VP Technical Information