AFCO's Hybrid rotor is the first, the strongest rotor on the market, and has been trusted by 1000's of racers and chassis builders for more than a decade.  Each rotor has been manufactured using premium grade alloys for superb thermal shock stability, double disked ground to ensure precise flatness, uses high strength 5/8" wheel studs installed on a 5 on 5" bolt pattern, and is rotationally balanced to reduce vibration and improve traction.  For the best stopping power, use AFCO brake pads with this rotor. You will not believe what you have been missing out on!