No Heat Sink Pad Shape: 50 Backing Plate: Steel Compound: Resin Fits Shimano Disc Brake Calipers (MT420, XT M8020, M8120) Shimano D03S Disc Brake Pads feature an organic backing plate, arriving with a steel plate and resin compound. They're specifically designed for Shimano BR-MT420, Deore XT BR-M8020, and BR-M8120 disc brake calipers.