Császár polyhedron

The Császár polyhedron ( Hungarian: [ˈt͡ʃaːsaːr], approximate English pronunciation CHA-sar) is a toroidal polyhedron without any diagonals; that is, every pair of vertices is connected by an edge. It is the dual of the Szilassi polyhedron. It is a regular toroid, but it is not abstractly regular.

It has 14 scalene triangular faces, 7 vertices, and 21 edges. 6 faces meet at each vertex.

Its vertices and edges are an embedding of the complete graph K7 onto a torus of genus 1.

It has the same edge skeleton as the 7-2 step prism.