The tail light on my e-bike went out and I was using this as a replacement. Unfortunately, it came off on the trail during some intermediate mountain biking over fairly rocky and rooty terrain, which would be my only complaint. For that kind of use, you may want to throw an extra little bungee on there like a red vine. However, I had used the light for a year or more and loved it, so when I went to order a replacement I got two. A typical Knog light--rugged, long charge times, very bright--plus it has that 270 degree visibility. I use it mostly on safety whips for dog trailers and my SO's tadpole trike. Those flags tend to rotate around a lot, but with this light at least some light as visible to drivers at all times.
My special project, a trike-cycle: Cobber light will be mounted on a tall fiberglass tube. The mounting strap piece will be epoxied to that tube. Now I have extra parts for experiments and replacements.
Compact, light and bright. Exactly what I was after. The side on visibility is also excellent.
Cobber Mount and Strap Set
I broke the original mount and ordered a new one. The design was improved and the light stayed right where I put it, even on rough mtb trails.