The O-ring,2.5x1.5 is the lowest priced item on this L. Front Brake Caliper schematic.
This L. FRONT BRAKE CALIPER assembly utilises two Seal Set,piston(s) - the highest specified component.
The seventeen Nsa700a Dn01 2009 (9) European Direct Sales / Mme L. Front Brake Caliper component parts are all listed in this schematic.