The compasses exists out of two parts: a branch, with a turnable compass spike and a point for drawing the circles, and a base to keep the compass spike in place. Three magnets in the base keep the compass tight to the board using the metal layer below the drawing surface.
The base consists of half a circle with a diameter of almost 6 centimeters, with three little legs pointing out, that way looking a bit like a round capital E. The middle leg has the shape of a triangular arrowhead of which one corner has been cut out. The arrowhead can be used to precisely place the middle of a circle on a specified point in the drawing.
The branch can be moved around the base clockwise and counterclockwise just above the sheet. By slightly tilting the branch it becomes easier to draw a circle with the point