Help with Rega tonearm


I'm in the process of redoing my whole system and am going through my vinyl equipment. I have a Rega tonearm complete with cables but for the life of me I can't recall what model it is. From my research I think it's either a RB600 or a RB700. There aren't any labels on the arm to say which model it is. Does anyone know how to differentiate the models?  I'd like to put it up for sale but want to price it appropriately so this would greatly help. 
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Which turntable?  P7 had the RB700; not sure what the P5 had.  P9 had the RB900 and RB1000.  Vinyl Engine could tell you what model of tone arm with which table.
Pics and description of various Rega models here:

https://www.vinylengine.com/a-guide-rega-tonearms.shtml
" Which turntable? P7 had the RB700; not sure what the P5 had. P9 had the RB900 and RB1000. Vinyl Engine could tell you what model of tone arm with which table. "

It may have been bought separately or came on a different brand of TT. If it has no model number on it, it probably came on a different brand. Either way, the OP needs to post a pic.
Thanks guys. I've been offline since the original post. Yes the arm was purchased separately from a member here several years back. I'll try to post a pic once I have the time and figure out how to do it on here!