The performance variants of the E53 X5 surprised many people with their speed, handling, and stopping capabilities. BMW achieved this by using a combination of softer composite brake discs together with a pad compound that, although highly effective, unfortunately causes the rotors wear down to their minimum effective thickness at a quicker rate than most. Maintaining the braking system is vital in such a quick and heavy vehicle. To ensure the X5's braking performance is upheld, we recommend replacement with Zimmermann discs. As an original equipment supplier to BMW, Zimmermann's discs are manufactured to the highest standards and come with their own Z-Coat to prevent the discs from rusting. Made in Germany.