Purchased this mount when I purchased the UT800 Headlight. It's a bit clumsy to use (not sure if it's the mount or the quarter turn adapter that comes with the headlight) but looks good with the overunder design. The issue is after only six ride my headlight when skidding across the road. After retrieving the unit I noticed the Mount had one of the ears broken off. This is the same issue I had with the original Edge 500 head unit. I contacted Garmin and the replaced both the mount and the quarter turn adapter. Fingers crossed it was an isolated occurrence.
Unfortunately, the 1031 has onofflap buttons mounted on bottom side edge rather than on the top face, so you need clearance between stembars and the bottom edge to hit the buttons. This has about 14 more clearance than any 1000 mount so lets you do that (barely). I found impossible to hit the buttons on a 1000 mount. I anticipate that it will be impossible to hit the buttons with full finger winter gloves even with this mount. Incredibly lousy button design by Garmin.