Fits ’17-Up E-Tec 850’s with the P-Drive Primary Clutch. Adjust from 12 grams to 20.6 grams. Easy adjustment with small 1.2 gram shims. Installs and adjusts in minutes. Comes with setup chart comparing to stock weights for reference. Better bolts – 5 mm allen wrench used instead of the 4 mm factory ones. Summit models can quickly adjust for low & high RPM without removing the ramps..