9-2 gyrochoron

The 9-2 gyrochoron, also known as mobius 9, is a convex isochoric polychoron with 9 ridge-truncated edge-truncated tetrahedra as cells. Together with its dual, it is the second in an infinite family of triangular dihedral swirlchora.

Isogonal derivatives
Substitution by vertices of these following elements will produce these convex isogonal polychora:
 * Ridge-truncated edge-truncated tetrahedron (9): 9-2 step prism
 * Mirror-symmetric heptagon (9): 9-2 step prism
 * Kite (9): 9-2 step prism
 * Isosceles triangle (9): 9-2 step prism
 * Edge (9): 9-2 step prism
 * Edge (18): 18-2 step prism
 * Vertex (9): 9-2 step prism