The drawing, which Leonardo calls Mazzocchio, is composed of 32 octagonal sections. It is a very complex axonometric projection, as each plane of the toroidal solid with its octagonal sections forms a hollow structure that reveals the one below.
This is not a simple exercise on paper. In the manuscript, Leonardo suggests a method for constructing a lead model and calculates the number of pieces needed for building it: 2048 in total.