Blocking system

I bought a giraffe of this type for photo club.
The product corresponds to what is advertised. The only complaint I can make is that the blocking system of the arm on the vertical leg comprises two toothed nuts plastic.
When adjusting the orientation of the vacuum giraffe there is no concern by cons when charging it takes two people (one to hold the arm and one to loosen / tighten) because you have to unscrew it completely the two nuts to change the screen and sometimes it's a little "sport".
Next time I will buy a giraffe equipped with a circular sector (a slit-shaped arc with tightening) which I think is easier to control, it must be gradually unscrew it without the whole plummets abruptly .. .