The brightness is satisfactory, is it a feeling that it seems to understand? I feel that the nut size for fixing can be used on one size anymore. Indeed it would be better if you are adjacent, but if it is the current size the spring washer is bigger so trying to use pliers with a spanner is difficult to grasp the washer instead of the nut. Of course, there is no problem if a spanner can be used. I am totally satisfied. I also want a blue light.