Check out any of the sixteen Rear Caliper components enlisted.
Parts such as the Rear Caliper: Bolt, Shim,outer, Caliper Assembly,rear, Shim,inner are included in the Gsxr750 1998 (w) (e02 E04 E18 E22 E24 E25 E34 E39) Rear Caliper parts fiche.
Of all the components used in this assembly the Caliper Assembly,rear is the most expensive.