20-2 gyrochoron

The 20-2 gyrochoron, also known as mobius 20, is a convex isochoric polychoron and member of the gyrochoron family with 20 ridge-septitruncated wedges as cells.

Each cell of this polychoron has mirror symmetry, with 2 octadecagons, 15 tetragons, and 2 triangles for faces, and shares a face with every other cell.