Determining Wire Size on flying leads

I have a CAN device that has flying leads on it that I need to attach a DTM connector to, The wires don't have any printing on the shielding and the seller gave me its a "probably" 18AWG. Is there a better way of finding out exactly what size it is?

You may be able to match the number of the conductor's wires, and it's overall conductor diameter, to a wire of the approximate gauge you think it is?

I have a set of automatic strippers for /32 tefzel wire. It's for very thin insulation, so when used against the proper gauge wire the jaw is pretty tight to the copper strands.

I figured out that I can use that as a 'gauge' to test unknown wires. I strip off a bit from the end, and then I clamp down with a smaller jaw size one at a time. And when the stripper bites into the copper strands, I know the wire gauge is one size larger than that.