Rear turn signal nut size?
By - ActualBacchus
I'll bet it's a 6mm
Would that be the inside diameter (or the bolt width)? The outside width of the hex nut looks a bit bigger (maybe 9-10mm).
Indeed it was. m6 stainless steel nut and a matching washer, about 40 cents.
Chances are the nut is still on the bike if the wires are still connected.