All-in-One Complete Front and Rear Brake Kit Replacement: R1 Concepts eLine Series Front and Rear Brake Kit comes with (4) high performance brake rotors High Performance Brake Rotors: Made of G3000 grade cast iron with rust protection for ultimate rust protection. Built with O.E.M specifications in mind, no modification required. OEM Specifications: Formulated with G3000/G11H18 cast iron specification, these premium brake rotors are engineered to match OEM specifications for durability, reliability, and stability. Non-Directional Finish - Each rotor is prepared with a non-directional finish to promote a faster and more even disc brake pad bed-in, along with quieter and smoother stops for longer lasting, consistent braking performance. Dependable Quality: Manufactured with multiple alloys for improved heat dissipation and performance. Mill-balanced for proper rotor function. Quality validated for proper metallurgy and correct brake plate thickness