Complete bolt-on and go rotor assemblies Made with forged aluminum center hubs, high-friction billet steel rotor rings and sturdy riveted construction Select front rotors available with SD-SystemÖ of square-sided buttons that allow the rotor to expand inwards and outwards unrestrained for perfect rotor functionality at any speed or load and increased durability Excellent choice when upgrading or replacing OEM brake rotors All rear rotors are solid mount. BRAKE ROTOR EBC MD661