SRAM Code R Pre-assembled disc brake Rear Rotor and adapter not includedSRAM Code R Disc Brake and Lever Front or Rear Hydraulic Post Mount Black A1. Built using the same architecture as the Guide brakes but with larger fluid reservoir and pistons it delivers even more power and heat management. Four aluminum pistons provide the stopping power and excellent heat management Stainless steel heat shield breaks the thermal connection between the brakes pads and the caliper body which reduces fluid temperature Forged aluminum