The GiroDisc slotted rear rotor for 2007–2013 Mercedes-Benz S63 and S65 (W221) is a rear-specific replacement rotor with slotted faces to aid in clearing pad residue and gases from the pad surface. That slotting supports consistent pad contact under repeated use. This rotor is intended for rear installation on W221 S63/S65 models as indicated in the product description.
GiroDisc 07-13 Mercedes-Benz S63/S65 (W221) Slotted Rear Rotors