Girodisc Mercedes G63 Front RotorsThe Girodisc system is a direct replacement for the OE disc, and includes caliper spacers and longer bolts to upsize the rotor to 410mm. No other modifications are necessary. By upgrading your brakes with lightweight high performance replacements as opposed to a big brake kit, your factory bias is maintained as well as your ABS efficiency. The central hat section of our rotor is made from strictly U. S. sourced 6061 T6 aircraft specification aluminum.