18-4 gyrochoron

The 18-4 gyrochoron, also known as rocky 18, is a convex isochoric polychoron and member of the gyrochoron family with 18 identical cells.

Each cell of this polychoron has bilateral symmetry, with 2 mirror-symmetric octagons, 2 mirror-symmetric hexagons, 1 rhombus, 4 kites, and 2 isosceles triangles for faces.