For Yamaha RD500LC 1984-1988 Front Rear Brake Disc RotorsFit for: Yamaha RD 1GE D769 500CC model year 1985 1988; Yamaha RD 500 LC 47X D467 1984 1988. Material: Laser cut 420 stainless steel, heat treated to ensure warp resistance. The slots or grooves on the disc provide an escape route for heat, gas and waste material, preventing it from building up on the contact surfaces. Wave design allows for better heat dissipation and water dispersion, the venting slots are designed to reduce the brake surface