Here's what I ordered.

 

Im using this 17mm mount for my Gamins. Have had on for 4 years, rubber sleeve keeps in place. Nothing fancy, its plastic, it does the job when needed.

 

This is the one (in Chrome) that I use for my Garmin. You just use one adapter...for your size bars. Works perfectly and positions it exactly as yours is pictured. Plus when the Garmin isn't mounted, it's very minimal in size and not obtrusive.