Motrax Micro Bar End Mirrors are for you if smaller is better or more stylish for your bike - these mirrors are a mere 74mm across.  They are convex, so you still get a wide angled view of what's behind you and have a multi-positional left or right bar end fitting.  The unique hidden fixing gives a neat finish.

 

They are sold as individual items, so to get two you have to buy two!