Rotors are Surface Induction Hardened with 12-14% Chrome Content for Superior Wear Characteristics Precision Ground for Trueness Machine-Punched for Accurate Mounting Holes Drilled Full-Sweep Pattern Provides Superior Heat Dissipation and Consistent Wet or Dry Performance Counter Bored Mounting Holes uses Stock Hardware or Chrome Buttonhead Screw Set 240-808 or Chrome Thin-Head Bolt Set 240-809 Polished front