For high performance and heavy duty street conditions the Porterfield R4-S compound remains a top performer in the realm of street/performance brake pads. With the R4-S compound giving a friction level up to .41. This is an amazingly fast stopping brake pad. Simply put, they will give you an impressive increase in stopping ability with very minimum amount of pedal effort. Perfect for prolonged everyday street driving while also being capable of enduring the most severe use without fade. It is also rotor friendly of course. We have gone to great measures to ensure that the R4-S compound has the absolute lowest noise and dust levels possible, far below O.E.M. equipment or any other high performance brake material. The R4-S compound which has an overall win in the Baja 1000 is available for most models of cars, trucks, and SUV's. Superb stopping power under heavy use. Great for occasional autocrossing, solo events, off road events and rallies. Perhaps one of the overall best performing, clean and quiet everyday high performance driving brake pad ever made. Set of 4 Pieces Rear for JAGUAR: 2015 XE 17/18/19 Rear for JAGUAR: 2017 XF/XFR 4CYL & 6CYL Rear LAND ROVER: 2015 Discovery Sport NOT FOR USE WITH CERAMIC ROTORS