The bracket must be tightened by hand. Unfortunately, this is so small that you can not muster enough strength to these contracting so tightly that the screen really is secure and does not move. For us was not the like in question, this to secure additional or with pliers tighten. On the one hand you have the tool is not always at hand, usually mounted on the other needs to the screen easily and can be removed again. He can do it fast and easy removal from the mount, but this can not hold in our buggy because the Buggy otherwise not be folded.
In our vacation we have fought exactly 2 days with this bracket and then abandoned totally unnerved and set the screen aside. Only it was so hot that one is even slipped immediately to this bracket with minimal sweat hands and she could no longer turn. Then (after so solid mounting as he could) the holder is still slipped at every major breath of wind. And when my 11 months old daughter could move the screen on its own so that it hung in her face, it was enough for me for good.
My conclusion: Stay away from this screen! That's a waste of money.