Transitional square double triswirltegum

The transitional square double triswirltegum is a convex isochoric polychoron with 54 identical cells. It is the third in an infinite family of isochoric square tegmatic swirlchora, the others being the small square double triswirltegum and great square double triswirltegum.

Each cell of this polychoron has bilateral symmetry, with 1 rectangular-symmetric hexagon, 4 kites, and 4 isosceles triangles for faces.