[mike1nw]

SO what tool do you use to tighten the mirrors, there is a small nut in a sort of well, a socket won't fit in there...
And what size is it... 8)

 

[john grinsel]

simple-----14mm open end wrench for upper, 17mm for lower nuts.

 

[cliffyk]

The odd nut, under the plastic cap, is set upon assembly (and the slotted upper end of the mounting stud upset) to preload the rubber cored snubber/damper, and "lock" the mirror shaft base onto the stud that then attaches to the brake cylinder frames--it is not intended to be adjustable in the field. The lower end of the mirror stud is locked into place by the 17 mm jam nut...

 

[mike1nw]

/\ Aha. So I guess they have some freedom to move.
I would like similar mirrors that don't stick up so far though. With same design. Might shop on JC Whitney