Rotor / disc features Ventilated design Rotor surface temperatures, which rise rapidly from repeated stopping (or slowing on mountain grade) can be held down to acceptable levels only by using a ventilated rotor to allow heat to escape, less expensive, non-ventilated rotors overheat, causing rapid brake pad deterioration, excessive rotor surface wear, and warping. Manufactured from cast iron Cast iron is the best material for rotors, it have superior wear characteristics at high temperatures compared to other types of steel, it will not warp. Pallet packing, or according customer's request