Dave don't go cheap at this point man.
Get the real mount and be happy the first time.
I got this one when I got the mirror and its AWESOME.
You really grabs the windshield frame with hidden tightening bolts. Also the mirror has a tilt down feature so you don't need to remove it when towing or putting the cover on. I love mine and would recommend it to anyone with the windshield mount mirrors.
https://www.amazon.com/2310-Deluxe-W...GQFA4H68ZGQSZ4