New Master Cylinder which fits 1968 - 1973 Opel GT 1.1L and 1.9L models. Original-style design features a 20mm bore and a switch for the brake warning light circuit. Also includes top reservoir seals and the master cylinder to booster o-ring seal. Will also fit 1971 - 1972 Manta & Ascona models equipped with the ATE booster. (Note: We also offer an upgraded "big bore" style master cylinder as part #4013-22).