Well left-field, but lest anyone finds themselves in my position...that's with hands trapped into the rear section of the bike trying forlornly to get to the original nuts* then this may be useful.
They are M12 x 1.25 thread (described as 'fine' I think).
The originals (I think) are flanged, but I got 'thins', or 'locking nuts' and also conventional 'nuts' and nylocks.
If anyone else wants to remount the original indicators elsewhere - that's what you need if you haven't got the original ones.
Conventional M12 nuts won't work - wrong thread.
I know - obscure
Would have put here 'Topic: V-Strom Information Compendium' but couldn't figure out how to
* Due to having a bespoke luggage system mounted I had to re-locate the original indicators and just couldn't bring myself to dissemble the entire lot and back of the bike just to get to the block connectors / mounting nuts