The Rear Master Cylinder (model K3) is made up of components including this Cylinder Assy,rr Master which is the most expensive.
Some items from this specific schematic: Cap, Diaphragm, Yoke, Hose,reservoir Tank.
The most reasonably priced component used on the Gsx1300rz Hayabusa 2001 (k1) Usa (e03) Rear Master Cylinder (model K3) is the Pin.