Product review (2 stars): Poor quality control
One of four fell apart when I tried to use.

These have a threaded insert that holds the "foot" part in.  I suppose this is good in that it would allow you to level the item you are attaching it to. However, one of these fell apart immediately upon use, as the threaded insert is too far in, and the foot only caught by maybe 1/2 of a thread.  I honestly do not know how to get the threaded insert to come out further.  I put it back together as best as I could, and GENTLY set the furniture upright.  I'm hoping it stays in place, but this is some poor quality control.