Girodisc Porsche 991 GT3 Rear RotorsThe Girodisc system is a direct replacement for the rear OE disc on the 991 GT3 and GT3 RS with OEM iron rotors. No modifications are necessary, allows use of factory unmodified pads unlike most aftermarket solutions for this application. 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 bias is maintained as