StopTech AeroRotors are patented 2-piece hat and rotor assemblies designed to replace original factory rotors while working with the factory brake calipers. Each StopTech AeroRotor Kit contains a pair of AeroRotors to fit the front or rear axle of your vehicle. Although the AeroRotors are a direct replacement for factory rotors, StopTech AeroRotors offer significantly improved cooling and overall braking performance thanks to several design enhancements and patented innovations. The 2-piece directional, floating AeroRotors are specifically designed to allow independent expansion of the rotor and hat without coning thanks to elongated drive pin holes. Available in MAX-float for racing, or controlled float for quiet street use, AeroRotor components include an AeroRotor friction ring with a patented AeroVane design and pre-assembled directional billet aluminium AeroHat with carefully engineered directional stand-offs to optimize cooling airflow. The panted AeroVane design pushes up to 61% more air for better cooling and reduced fade on the track. By using lightweight aircraft-grade aluminum for the hats, the 2-piece AeroRotors are up to 8 pounds lighter than stock rotors. The lighter rotational weight allows for faster acceleration and deceleration, and nimbler handling. StopTech AeroRotors are available in slotted or cross-drilled finish. Slots and holes allow better dissipation of heat, friction material and debris - assuring fresh pad material is in contact with the rotor face every time. An optional anti-corrosion gold zinc coating benefits customers who live in cold climates, where snow and road salt are commonly encountered. Zinc coating also benefits customers who prefer no visible surface rust on the vanes and outer circumference of rotors. StopTech AeroRotors are 100% made in the USA, with both casting and machining taking place in California. *StopTech AeroRotor Rings* The patented 2-piece AeroRotor assembly uses uniquely designed and patented AeroVanes inside the disc to optimize airflow through the rotor. This improved directional design minimizes turbulence and flows up to 61 percent more air than any other rotor tested. The result is up to 80 percent better airflow over original equipment rotors and 10-30 percent better airflow than other directional vane racing rotors currently available. Better airflow equals better cooling, and better cooling means less fade and better overall brake system performance. StopTech AeroRotors also feature a proprietary alloy chemistry. By adding molybdenum to the gray iron, carefully targeting a narrow range of hardness and tensile strength values, and controlling the cooling rate of the rotor after casting, StopTech produces a friction ring with added crack resistance as well as improved functionality. *Drive Pins* In certain applications where packaging is an issue - such as on the Chevrolet Corvette - StopTech uses slant-head drive pins to provide improved clearance as pads wear. *Zinc Plating* Zinc Plating, available on StopTech AeroRotors, prevents corrosion. This is particularly useful in winter climates where road salt and other environmental factors may increase the likelihood of oxidation.