Small stelloctagonal expandiduoprism

The small stelloctagonal expandiduoprism, or sisoxdip, is a nonconvex scaliform polychoron that consists of 64 regular tetrahedra and 16 blends of 2 small cubicuboctahedra and octagonal prism. 2 tetrahedra and 4 blends join at each vertex.

It is constructed as a blend of 2 steth and 2 shado, or alternatively 4 steth and 4 sodip. It has the same symmetry as the octagonal duoprism.