Check out any of the eighteen Rear Master Cylinder components enlisted.
Parts such as the Rear Master Cylinder: Piston-comp-brake, Cylinder-assy-master,, Clamp, Rod-assy-brake,rr are included in the Ksf250-a10 1996 Europe Rear Master Cylinder parts fiche.
The most reasonably priced component used on the Ksf250-a10 1996 Europe Rear Master Cylinder is the Bolt-flanged-small.