Well, I also have a Fenix light for my helmet. I haven't mounted either yet, and since the days are getting longer now I likely won't need them for a little while. But, I would like to be able to use them sooner rather than later. I might want to get out and ride at night some this spring/summer, so I think I'm going to go ahead and get the FSA add on. Anyone used this specifically for a Dinotte light? Any issues with mounting or sturdiness?