I decided on these lights after reading a great many reviews of these and others. The lights arrived very promptly and I tested them out that night without putting them on my bike. They were great. The front light is really bright - even on the dimmer setting - and the back light is very good, too. So I put them on my bike. That was when the disappointment set in.
The front bracket is rubber, so quite easy to fit on the handle bars. However, I recommend using a washer (not supplied so find one), as the screw head is only a tad wider than the hole.
The back bracket is very flimsy. The screw head chewed through the bracket resulting in the light's clip separating away from the rest of the bracket. I had to re-jig the whole bracket to get the light to stay. This is a design flaw, exacerbated by the cheap, soft plastic construction.
The lights themselves I would give 4 stars. They are bright and easy to use. The only thing I don't like about them is that you have to go through all the flashing options on the back light before they switch off. I would have prefered a simple on-off button - but I guess that's down to personal preference.
It's the brackets that let the package down. If you want a good torch with a clip and red light you can clip onto a rucksack, then these are the lights to go for. If you want them on your bike, be prepared for some re-engineering.