My old quick nut, I had more than 10 years. Really great that almost always leave the windows change the angle without tools. Simple enough tighten the nut by hand, in solving hand it makes "click" and the mother can easily unscrew by hand. If an exception does not go to open by hand, unscrew the nut necessarily with special key on the two holes. With pliers I have brought in such a case, the hardened outer ring to burst and then a new mother was due.
