There seem to be two versions of this mount. I purchased an Edge 820 a couple of months ago. The mount packaged with the 820 seems to be a little beefier. mounts to the left of the stem, the clamp screw is behind the mount and the computer is positioned above the top of the stem. I have purchased two additional mounts to use the computer on additional bikes. The accessory ones are as pictured and mount to the right of the stem and position the computer lower. I prefer the packaged version but the accessory ones get the job done.
September 2018, four local cyclist were by a car. The three that survived suffered multiple injuries and brain trauma. Hearing the news I immediately purchased a Garmin Varia radar system. It is an amazing aid to cycling safety. Using it and a good rear view mirror has eliminated any surprises from approaching cars . Upon witnessing the benefits I purchase a second mount as that I always have the Varia working for me. The forward mount places my Garmin 520 in the perfect location to allow me quick glances to get all the info I need for performance and safety. If one rides on the open road then improve your safety with the aid of a Garmin Varia.