Enneagonal-dodecagonal duoprismatic prism

The enneagonal-dodecagonal duoprismatic prism or etwip, also known as the enneagonal-dodecagonal prismatic duoprism, is a convex uniform duoprism that consists of 2 enneagonal-dodecagonal duoprisms, 9 square-dodecagonal duoprisms, and 12 square-enneagonal duoprisms. Each vertex joins 2 square-enneagonal duoprisms, 2 square-dodecagonal duoprisms, and 1 enneagonal-dodecagonal duoprism. Being a prism based on an orbiform polytope, it is also a convex segmentoteron.

Vertex coordinates
The vertices of an enneagonal-dodecagonal duoprismatic prism of edge length 2sin(π/9) are given by all permutations of the third and fourth coordinates of: where j = 2, 4, 8.
 * $$\left(0,\,1,\,±(1+\sqrt3)\sin\frac\pi9,\,±(1+\sqrt3)\sin\frac\pi9,\,±\sin\frac\pi9\right),$$
 * $$\left(0,\,1,\,±\sin\frac\pi9,\,±(2+\sqrt3)\sin\frac\pi9,\,±\sin\frac\pi9\right),$$
 * $$\left(\cos\left(\frac{j\pi}9\right),\,±\sin\left(\frac{j\pi}9\right),\,±(1+\sqrt3)\sin\frac\pi9,\,±(1+\sqrt3)\sin\frac\pi9,\,±\sin\frac\pi9\right),$$
 * $$\left(\cos\left(\frac{j\pi}9\right),\,±\sin\left(\frac{j\pi}9\right),\,±\sin\frac\pi9,\,±(2+\sqrt3)\sin\frac\pi9,\,±\sin\frac\pi9\right),$$
 * $$\left(-\frac12,\,±\frac{\sqrt3}2,\,±(1+\sqrt3)\sin\frac\pi9,\,±(1+\sqrt3)\sin\frac\pi9,\,±\sin\frac\pi9\right),$$
 * $$\left(-\frac12,\,±\frac{\sqrt3}2,\,±\sin\frac\pi9,\,±(2+\sqrt3)\sin\frac\pi9,\,±\sin\frac\pi9\right),$$

Representations
An enneagonal-dodecagonal duoprismatic prism has the following Coxeter diagrams:
 * x x9o x12o (full symmetry)
 * x x6x x9o (G2×I2(9)×A1 symmetry, dodecagons as dihexagons)
 * xx9oo xx12oo&#x (enneagonal-dodecagonal duoprism atop enneagonal-dodecagonal duoprism)
 * xx9oo xx6xx&#x