It is my impression that there are two styles.
I have one that uses a knob with a threaded shaft to tighten the jaws against the track's rails. Then you use a lever to either assemble or disassemble the track.
I believe there is another version that has a level (with a cam?) to tighten the jaws against the tracks rails.
Can anyone confirm this?
I picked mine up second hand, and have not updated my track plan since. So I have not tried it.