I was searching for a good way to replace my stock mirror on my beta rrs, and by looking at what's on the market right now (like the doubletake trail mirrors), I came up with this design. It uses “blind spot mirror 2 inch frameless” that you can find on amazon or anywhere for like 7 $ (cad) per pair.
if you get the right mirror, it's press fit, no need of any glue.
it also use 1 m5x30 screw and bolt per mirror
EDIT: After running those 2 inch, I wanted something a little bit bigger, so I made the 2.5 inch (using frameless 2.5 blind spot mirror). First picture is the 2.5 inch, second picture is the 2 inch.
The author marked this model as their own original creation.