The Porterfield R4-S compound is the perfect solution for those drivers who see a fair bit of track time but also drive their cars on the street. The R4-S compound is renowned for being very progressive and easy to modulate on the street while still providing desirable heat characteristics on the track. Also, the R4-S compound has exceedingly low noise and dust levels, far below OEM equipment or any other high performance brake material. Pick up a set today and start realizing your braking system's true potential!