i think most people get the point when you say rs now though. considering how popular they are, and as opposed to dayton, nothing wrong with them, but, if someone said rs, i wouldnt be thinking of daytons.It says 12" rs , and you give no other information.
Trying to help you clear it out.
Maybe 12" dayton RS ? http://www.partsexpress.com/pe/showdetl.cfm?&Partnumber=295-464