A concave polar zonohedron with 20 faces and 5-fold rotational symmetry. The 10 faces with a vertex at either end are square. The 10 identical rhombic faces surround the equator, just the opposite of it [convex cousin](https://skfb.ly/6yOXW).
Made with [vZome](http://vzome.com). The download includs the vZome file.