BikeMaster Front Contour Brake Rotor BMW K / R Features Contour circumference designed to increase edge surface area for more efficient cooling Developed specifically for increased braking ability and longevity Bolt-on performance due to less unsprung weight and braking surface materials with high coefficient of friction Computer-aided design ensures maximum strength and minimum weight Ground to ensure perfect concentricity and parallelism to prevent warping CNC billet machined aluminum carriers for accuracy, strength and lightweight Laser cutting for accuracy to the ten thousandth of an inch BikeMaster M.a.s. Technology (Maximized Area of Surface) Made in Spain