Bluestuff NDX is a high friction sport and race material that can be used for aggressive street driving and certain types of track use. The material has had much success on the track with quality aftermarket calipers (Multi piston systems with better release and cooling and larger rotors) and limited success with street based calipers where pad size and caliper drag can challenge any brake material. The biggest advantage of EBC Bluestuff NDX is their bite from cold and progressive brake feel and the ability to bring a car to a complete stop. This has led to the ECE R90 brake safety regulation approval of R90 which is now completed and certificates are being obtained (during July 2011). There are certain older street based caliper systems where even the new Bluestuff will have trouble handling the caliper and slider drag inherent in the systems but this scenario is exactly the same for our competitors. There is NO material that will be PERFECT on the track in all older street based caliper systems. Bluestuff NDX Full Race Brake Pads; FMSI Pad No. D991; Vented; 350mm Dia.; 69.4mm Height; 33.8mm Thick; 98.1mm Center Hole Dia.; Pad Dimensions: 190.2 x 101.8 x 16.3mm; 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 Front Bluestuff NDX Fastest Street and Race Pads FMSI D991 2009 thru 2012 PORSCHE 911 (997) (Cast Iron Rotor only) 3.8 Twin Turbo