Enneagonal duotegum

The enneagnoal duotegum, also known as the enneagonal-enneagonal duotegum, the 9 duotegum, or the 9-9 duotegum, is a noble duotegum that consists of 81 tetragonal disphenoids and 18 vertices. It is also the 18-8 step prism. Together with its dual, it is the first in an infinite family of enneagonal dihedral swirlchora.