4-Piston Rear Brake CaliperDirect, bolt-on performance upgrade, compatible with original master cylinder4-piston caliper, CNC machined out of billet aircraft aluminium, black anodized and laser marked4-piston design provides significant power increase over originalBrake pad size/thickness is double compared to original (SX50), this dramatically increases brake pad lifespanRigid design eliminates any caliper flex and ensures maximum durabilityMatching Moto-Master brake pads PART #s 1721-1282 (11 compound), 1721-1283 (12 compound) and 1721-1869 (21 compound)