This schematic depicts all components used in the Rm250 2004 (k4) Usa (e03) Rear Caliper (model K1/k2/k3) partslist.
The most reasonably priced component used on the Rm250 2004 (k4) Usa (e03) Rear Caliper (model K1/k2/k3) is the Washer.
On this parts fiche the Bolt is the most specified component.