Russell's stainless steel Pro Polish brake rotors feature a exclusive E.F.S. process producing the only mirror finished brake rotor Pro Polish Rotors are held to exacting specifications with near perfect flatness and surface finish The end result is a precision product with zero runout desired by custom bike builders and serious enthusiasts Custom designed Pro Polish rotors, in the 5-Spoke and Turbine designs, are precision cut utilizing the latest high-pressure water jet technology This process eliminates metal distortion while still maintaining the metal's integrity Manufactured from SVS420JZ stainless steel, Russell Pro Polish Rotors are highly rust resistant and are compatible with most types of brake pads, including sintered material and Kevlar Unique hole patterns deliver the optimum in heat dissipation, providing the maximum in braking efficiency Fit FX, FXR and Sportster 1977-1983 equipped with dual disc front brake (OEM 4413777A), 2.4 ID.