A sample from the products for the Rear Caliper include: Bleeder, Seal Set,piston, Bolt(8x28), Shim,pad.
The most reasonably priced component used on the Gsxr1000z 2004 (k4) Usa (e03) Rear Caliper is the Bolt(8x28).
eleven components are shown in this Gsxr1000z 2004 (k4) Usa (e03) Rear Caliper exploded diagram.