New old stock that came to me in a job lot of Yamaha mirrors.

It is unboxed, but I haven't managed to pin down yet which bike(s) it was originally fitted to. The length of the thread makes me think it would be a clamp type fitment and the black backing of the mirror suggests late 1970s or early 1980s. 

Some dimensions:-

Diameter of thread - M8

Length of threaded area - approx. 37mm

Size of hexagon head of nut - 14mm

Distance from top of thread to centre of first elbow - approx. 52mm

Distance from centre of first elbow to centre of second elbow - approx. 173mm

Distance from centre of second elbow to where arm enters mirror body - approx. 30mm

Diameter of mirror (glass only) - approx. 99mm

Diameter of mirror including frame - approx. 111mm

Obviously it can be fitted to any Yamaha of the buyer's choice.

Please satisfy yourself that this is the part that you want before buying. I am happy to provide more info, measurements and photos upon request.