Not bad, but to use only for lightweight equipment.

This folding-angle rail is inexpensive and well made. But stops at my Nikon D90 is not sufficiently strong.
I have the screw so tight that I have to worry about damaging the camera thread.
As soon as I but the camera slightly inclined from the horizontal, the rail with mounted flash unit on its own twists.

I probably can not even return the track because I had to destroy the package to unpack.
I find that very annoying.