This parametric design is a sanding tool for printed gear. It should be used as a sand paper support to access the inside parts of spur gears.
The geometrical significance of all parameters is explained in the graphic in the images representing the tools cross section. Only the parameter L is not represented and decides the length of the tool.

For detailed explanations on how to use a customizable part look here: https://www.instructables.com/Learn-How-to-Use-Customizable-3D-Models-With-OpenS/