A simple geometry kit. This currently includes a compass, the radius is adjustable based on how far screwed in the two pieces are. The hole in the drawing piece should support most standard mechanical pencil leads. The triangles and just a 30 60 90 and a 45 45 90 triangle. I plan on adding more pieces from a middle school geometry kit soon. I would recommend printing at pretty good quality so the threads don't get messed up.