Made from heat treated carbon steel with higher friction than stainless steel equals more stopping power the outside diameter is shaped to provide extra pad cleaning ability. YOU WILL NOT FIND A BETTER QUALITY DISC AT THIS PRICE. PLEASE NOTE THESE DISCS ARE MADE FROM CARBON STEEL AND HEAT TREATED. EXCELLENT QUALITY. Available to fit Gas Gas, KTM,Yamaha,Suzuki, Honda and Kawasaki.