Front PFC brake pads for 991 GT3 Cup cars. Also fits Cayman GT4 Clubsport. Performance Friction's 331-compound is engineered for endurance applications where a smooth initial bite is desired. Designed as a front-specific pad. The 331 is engineered around ABS-systems in order to help prevent undesired lockup. Ideal for heavy, fast, high-downforce cars where lots of initial bite is desired. The 331-compound continues PFC's tradition of long life, excellent disc conditioning and smooth bite/release.