I needed a new light after my bike light fell off my dog's collar and surprisingly I could not find it even though it was dark. I was in the store looking for a similar bike light but they were out of stock so I bought this.
It is better in some respects as it is almost a complete ring of light (first time I've come across an application of total internal reflection). The bike light was brighter but often slipped below his neck so it wasn't always visible.
Cutting it to length need something a bit more robust than the scissors shown on the packing. The first time out the free end popped out when he was on the lead so it could have been lost. I solved this by putting a couple of small zip ties on the silicone tube/shroud to ensure the ring could not pop out.
Only time will tell how long the batteries last but so far I'm quite pleased with this.