The 034Motorsport 2-Piece Floating Front Brake Rotor Upgrade Kit for the BMW F8x M2/M3/M4 is a complete replacement 380mmx30mm brake rotor kit, designed to work flawlessly with the factory front calipers found on the BMW F8x M2/M3/M4. Weighing in at approximately 23.8lbs, each rotor reduces rotational weight by 0.2lbs on each corner over the factory 24.0lbs rotors. While reducing weight, the rotor retains proper thermal mass in the rings to adequately capture heat, while utilizing 72 directionally curved vanes to forcefully flow cool air through the rotor to dissipate heat.