All EBC rotors including USR Slotted 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 matching high friction brake pad set. Having sold hundreds of thousands of brake kits EBC Brakes feel confident their approach is as perfect as it gets.We are of the opinion that slotted rotors have been “Over sold” by certain marketplace participants and our findings are that a slotted rotor will only give benefits if used with a pad that compensates for its reduced surface area.DO NOT FIT UPGRADE PADS TO REAR OF VEHICLE UNLESS SAME UPGRADE FITTED TO FRONT, The Thermic Black coating does NOT need to be removed before install. Do NOT use brake cleaner or any other method to remove Thermic Black coating from discs rotors. The Thermic black coating will be removed in the pad swept area by the brake pads with in the first 10 to 20 stops made after installation on the vehicle. The Thermic Black coating is an anti corrosion coating for long resistance against rust. Attempting to remove Thermic Black Coating with brake cleaner or any other method is NOT covered under EBC warranty.