EBC 12+ Audi A6 Quattro 3.0 Supercharged USR Slotted Rear RotorsChoose from EBC plain non drilled rotors or sport rotors in two choices wide aperture 3GD series for cooler running or new SUPER SILENT Ultimax USR slotted series. All EBC rotors are British made and are precision machined in the UK. Rotors are made from high quality grey iron to exacting standards and undergo extensive testing and rigorous quality control. Slotted rotors can significantly improve brake performance and longevity when used with a