The extension arm is not long enough for my Edge 1000. When mounted as directed on a 31.8 mm handlebar the GPS device cannot be rotated into position with out the corner of the device impacting the handlebar clamp face. Considerable force is required to rotate the GPS into position, and even then the bottom of the device is crammed against the clamp face and subject to every vibration that the handlebar feels. I bought this solely so I could position the GPS away from the handlebar grip area as seen in the advertisement. I have the same product which works well on a smaller handlebar. The person who designed this should have made the arm a few millimeters longer. Stupid design mistake, and misrepresented in the advertisement.
It's way easier to see your bike computer on the out-front mount instead of on the stem. My only real complaint is that for the cost of the Garmin computers they ought to include the out-front mount instead of having to purchase it separately. Oh well.
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.
Expensive!! OK, I know they probably don't make a lot of these, but $40 for some plastic is a lot.
However, it is a lot better than the rubber-band thingy that Garmin provided w/ my Edge 500. It pushes the computer out in front so it's a lot easier to see without having to take your eyes off the road.