3R Blind Spot Mirror.

I thought it was goofy looking.
I decided to mount it to the mirror and try it out.
I was going to use it for my drive to work and then return it. ($7.48 is the cost)
It's still on there and it works great!
Once it's mounted to the mirror, you can adjust the mirror up, down, left and right.
You make the adjustment using the glass itself not the housing.
I mounted mine to the top of the mirror like is says and it really doesn't look as goofy as I thought it would.
It has a nice wide viewing angle and the mirror objects are large enough to see.
There's a point where a smaller blind spot mirror isn't effective and the main mirror needs to used.
This mirror very usable and is the right size for me and my older eyes.
When I used it to merge on the highway, I was able to see across all 4 lanes at the same time.
Very nice. I like it and its staying. (It is removable)
I'm finding I like this better than the stick-on blind spot mirrors I've used in the past. 
Amazon Link