The EradiSpeed+ is a direct replacement 2pc rotor for the 2013-2014 Mustang GT500. This is designed to work with the factory Brembo brake system. These 15 inch rotors feature directional vanes advancing cooling efforts, and are a 2pc design with an anodized black 6061-T6 aluminum center hat bolted to the rotor ring, which greatly reduces weight.Rotor Diameter:15 inch 2-piecePiston Count:Uses your existing stock calipers.Pad Type:Uses stock pads.Includes:15 inch 2pc rotor assemblies for front rotors upgrade (sold in pairs)Notes:Designed to be used on the 2013-2014 factory Brembo Mustangs brake systems.