I Really should have read the reviews. It may look nice but the lights are not secure enough.
It is difficult enough to get the large bolts tightened, but there should be a small nut on the arm described as B. I could not find one anywhere in the packaging, so I actually went to HD and bought 8 32nd nuts and tried to put them on the thread I managed to get one on but the other 2 were impossible to get to. Seems you can not tighten those arms enough not to let rain and all through. Seems the only solution would be to seal the gap with sealent.
Poor design and manufacture.