Exedy 04-14 Subaru Impreza WRX STI H4 Stage 1 Replacement Organic Clutch Disc (For 15803HD)Stage 1 Organic ULTRA Fiber Disc facing material provides the high heat resistance essential for motorsports. It was developed by reviewing both the copper wire ratio and the composition of the high strength fiber. The ULTRA Fiber Disc maintains the superior half engagement feeling specific to the Organic material. With improved high heat resistance, it provides the functionality essential for street performance and mild racing applications. This Part