This dual action dual piston rear caliper provides superior stopping power. This caliper will work with 10 inch brake rotors using a boomerang type caliper support #E50261 or the Y type caliper support #E50381 and will work with 11 1/2 inch brake rotors using the Y type caliper support #E50380. Sold completely assembled with all internal components and includes brake pads and pins, replacement boomerang bushings, support spring, rotor spacers, mounting hardware and instructions. Fits FX '81-'82.