Parts such as the Rear Master Cylinder: Connector, Hose,rr Brake, Cap, O Ring are included in the Gsf600s 1999 (x) (e02 E04 E17 E18 E22 E24 E25 E34) Rear Master Cylinder parts fiche.
With four applications this Washer(10x15x1.5) is the most specified part.
Of all the components used in this assembly the Cylinder Assy,rr Master is the most expensive.