S&S 3-piece flywheels with integral main shafts are the strongest yet, made from 4140 steel and feature a larger 1.671" crankpin. Flywheel assemblies are designed for use with OEM-style roller sprocket shaft bearings. Fit directly in stock crankcases with no modifications. For 88", 95" and 100" displacement in Twin Cam A and B motors with 4" stroke, and 96"/103" Twin Cam A and B motors with 43/8" stroke. Made in the U.S.A..