Building on the same platform of our previous generation Pro Series Rotor, the Spidertrax Ultimate Rotor delivers many of the competition proven benefits our brake rotors are known for, but at a fraction of the price. We start with domestic grade laser cut mild steel plate, then CNC all Ultimate Rotors using our unique slot pattern optimized for achieving excellent pad wear. All of this while boasting a massive 14″ (355.6mm) diameter, the key for superior Ultra4 stopping power at both high and low speeds. If youre an Ultra4 racer who likes to go fast, but needs to watch that budget while doing so, the Ultimate Rotor is for you. This Ultimate Rotor is designed to work with Spidertrax 6½” (152.4mm) BC Hats. Rotor measures 3/8″ (9.5mm) thick. To clear the diameter of this rotor, a 17″+ (431.8mm) wheel is required. Brake Hat mounting hardware included.