Here is a better photo. I went back to the site and got the dimensions, and then added a Coke can in scale. It is bigger than it looks in the close up photos. It is really three levels:
(1) The large base with casters and four screw legs.
(2) A turntable with three locking screws.
(3) A circular platform with a large ball joint with four locking screws.
Not sure what the thumbscrews on the highest platform are for.