Popular brake disc for Mazda Familia/Premacy/Mazda3/Mazda6/CX-5/CX-7/RX-8/RX-7/BT-50,Website:http://www.lzyhbrake.com,material is gray cast iron to meet HT250(G3000)stardand,Hardness:180-240HB,stable coefficient friction,low noise,no dust,long service life.