I bought this mirror to go with my shimano handlebar shifter/break lever and it's superb !! it's in a perfect position to let you see right back down the road with the smallest of eye movement, is easily adjustable , and doesn't at all interfere with your hands anywhere on the drop-handlebar. I'm not the world's best fixer of things but didn't find any problem with using the instructions and the allen keys supplied to fix it into place in about 5 mins. It needs some quite hard turning of the allen keys but not excessively so, and , as it means it doesn't come loose again (mine hasn't after a week's cycling = 50 miles), it's worth it.
It vibrates a bit but only on quite a rough road surface but which bike mirror doesn't?
For my last bike I had a mirror which I had to attach into the tube of the end of handlebar. That meant quite a big eye movement away from the road in front. The mirrycycle mirror is soo much better.
I'm really pleased with it, and it's made me feel so much safer on my bike that I wouldn't want to be without one now. It only goes with certain shimano shifter/break levers unfortunately. Luckily, my new bike is one of them. Sorry for you people who haven't got that type. You will not regret buying one if you have.
Watch out that your shifter/break lever really is compatible though. Some shimano ones in fact are not, and it is a little difficult to check. The instructions tell you to look for a number on your lever under the rubber material on the hood which you then need to check against their little printed chart. I couldn't find this number there . Luckily, it was the right one in my case.