Russell Vintage Stainless Steel Rotor For Harley Features: Manufactured from Svs420Jz, a highly rust-resistant stainless steel material compatible with all types of disc brake pads (including sintered pads) Unique hole patterns deliver the optimum in heat dissipation, providing the maximum in braking efficiency High-frequency induction hardening, o.d. trueing and tempering prior to final surface grinding Computer-controlled process guarantees quality control and precise dimensions Outside Diameter 254 mm / 10 Fit FX 1978-80 rear, FL 1978-80 rear and 1978-84 front (Oem 41813-79), 2 ID. Replaces OEM 41806-72 / 41807-73 / 41813-79