EBC 06-09 BMW Z4 3.0 Si USR Slotted Front Rotors are a performance upgrade for the front brakes of the 2006-2009 BMW Z4 3.0 Si. These slotted rotors are designed to improve braking performance and reduce brake fade under hard braking and high-speed driving. The slots also help to reduce brake dust, providing a cleaner, more attractive look to the wheels. The rotors are made from a high-grade cast iron for increased durability and strength.