The EBC 03-09 BMW Z4 2.5 BSD Rear Rotors are a set of high-performance brake rotors designed to fit the 2003-2009 BMW Z4 2.5. The rotors feature a BSD (Black Slotted Disc) design and are made from a high-grade cast iron for maximum durability and performance. The rotors are designed to improve braking performance in both wet and dry conditions and reduce brake fade. The BSD design also helps to reduce brake dust and noise.