RC, that is for the FRONT not the REAR.
As far as I know there are no replacement bushings, as they are cast into the arm. (they're also known as Lateral Links, as opposed to control arms, in the rear)
You may be able to find a matching size in urethane replacements. I've not looked into it though. I think they designed it for the whole link to be replaced, with a few other Mazda cars that is the case.