Sram Disc Brake Pads - Organic/Steel (Quiet) - Code 2011+/ Guide Re:

To keep your Avid brakes functioning properly, check your pads for wear and replace them when necessary. Organic compound pads are softer for quieter braking and increased modulation, while metallic pads dissipate heat better and last a bit longer. Two pads, one retraction spring and a mounting bolt are included (enough for one brake) in each pad set. And, choose an aluminum backing plate if you're really counting the grams.