I got a pair of adjustable mirrors that attach to the bar ends as shown in the photo.
they have a detent so that if bumped they will move (swivel around,)before being damaged. The mirror is 80 mm. dia. and are fitted by bolting into the bar ends. I had to slightly modify the attachment bolts but it was an easy fiddle.
They work very well, quality is OK. I got them because my teardrop trailer was too wide for an effective rear view using the standard bike mirrors.
These ones are easy to adjust whilst on the move.
I think that I got them from the Alibaba sellers at somewhere around the $40=00 mark with their free postage.
The took some searching to find them as i wanted the extra detent function in the adjustability , which most of the mirrors on offer did not have.
Cheer , Winston66