Spider performance brake rotors feature titanium floating rotor hardware, jagged brake discs & CNC machined lightweight billet carriers Outer brake disc is made from high carbon 420 stainless steel, laser cut then CNC machined to remove all hard edges for a smooth feelFloating rotor hardware is CNC machined from solid TitaniumArlen Ness hub kit required to complete wheel on ABS or non-ABS Harley applications.