I was riding around Chicago feeling like a ninja, wearing all black. NInjas are awesome until they get hit by cars, so I decided I needed to be a bit more visible. This bag definitely is doing the job. The only potentially negative comment I have about the bag is that the reflective material is stiff and creases with minimal use. So far I don't mind how this looks (I tried to upload a photo...), but I wonder how it will look down the road with lots of wear. I also wish it had some kind of external U lock holding mechanism, but that's also not a huge deal. Other than that, I love that its waterproof, and I find that the medium size fits my 5'4 frame well.