Girodisc Ford S550 Mustang (w/ Brembo) Front RotorsThis is a 380mm x 34mm rotor for use with the S550 Mustang GT with the optional performance package six piston Brembo calipers, including all Bullitt and Mach 1 models. The Girodisc system is a direct replacement for the OE disc. No modifications are necessary. The disc will bolt directly to the car and work with OE calipers perfectly. By upgrading your brakes with lightweight high performance replacements as opposed to a big brake kit, your factory