This form was a graduation gift from my wonderful parents. They knew how much I loved working with the school ones during my program and thought I should have one for my future career.
I get asked a lot if it is my exact size (it is not) and why it isn't an adjustable size. The reason for this is that it is a professional form. When commercial patterns are drafted, they are usually developed in a medium size (typically 8 or 10) and then graded up or down. The eight is a little bit larger than I am, and for personal sewing it is easier to take things in after draping rather than enlarge them.
I also get asked a lot why it says "collapsible shoulder" on the hips. That is because the shoulders are spring loaded and can retract into the body. This allows for fitted garments to be slid onto the torso. Imagine if you were getting into a tight fitting garment, your shoulders typically contort to fit through the waist seam.