Ultra-light friction ring CNC-machined from high-carbon steel Clean, uninterrupted solid rotor look due to a locking 302 stainless spiral retaining clip in the back Entire rotor weighs 3.6 pounds A life-time manufacturer's warranty applies to the friction ring only if Lyndall Brake Pads are used on the rotor at all times. Each friction ring is individually serial-numbered for quality control.