Milwaukee Twins Disc Brake Rotor For Harley FX / XL The Milwaukee Twins Disc Brake Rotor combines aesthetics with functionality, featuring a zinc-coated finish that resists corrosion with vented design for better cooling. It is precision-engineered for a true fit, ensuring it directly replaces the OEM rotor, delivering reliable performance and compatibility. Formerly offered under the J&P Cycles brand. Features: Vented Zinc finish 10 diameter Precision ground for trueness Replaces OEM 44137-77 A