The hexagonal concave unit, introduced by origamist Tomoko Fuse, is a modular origami elementary component, which alows to build a lot of polyhedra. Infringing the rules of pure origami, one can widen the range of its applications. This paper shows some possible extensions, and hopefully may let other people find other extensions.

This activity is meant for every one, from children to mathematicians : the module is easy to fold, easy to assemble in large units.