Wilwood Master Cylinder, Aluminum Tandem Chamber Disc Brake Conversion with Adjustable Proportioning Valve 1.125" Bore, Standard (1) master cylinder (1) prop valve (1) tube adapter, 1/2-20 X 9/16-18 (1) tube adapter, 1/2-20 X 1/2-20 (2) tube adapters 1/2-20 X 3/8-24 Total pistion stroke of 1.10" is distributed at a 2:1 volume ratio between the primary and secondary chambers Fabrication or modification of the pedal and push rod may be required on the 1" or 1-1/8" bore size to adapt the master cylinder to some applications