Yes to pass the time away I have devised a new quiz called "Guess that bolt". It's fun for all the family

Ok the bolt in question is the one on the right and it could be from the fairing, engine, carbs, brakes and maybe a few other places. Any ideas? Trouble is with this quiz I spent ages at it, I don't know the answer, it was left over in a bolt pot with a few others that I did know what they were and I've replaced?
The one on the left is a M6*20 cap end stainless for scale, the other ??????