The R1 Concepts Geo-Carbon drilled-and-slotted rotor for the front left of 2004–2010 BMW 528i xDrive applications is a replacement rotor combining drilled holes with slots to assist heat management and surface cleanliness under braking. Specified for the 528i xDrive front left position, it’s meant as a service replacement when addressing worn front rotors on those BMW all-wheel-drive models.
R1 04-10 BMW 528I Xdrive Front Left Drilled & Slotted Geo-Carbon Rotor