Heptagonal duotegmatic alterprism

The heptagonal duotegmatic alterprism is a convex isogonal polyteron that consists of 2 heptagonal duotegums and 98 isosceles triangular-triangular duotegums. 2 heptagonal duotegums and 21 isosceles triangular-triangular duotegums join at each vertex. It can be formed as an alterprism of a heptagonal duotegum, or as the hull of two opposite heptagonal disphenoids.

Using the ratio method, the lowest possible ratio between the longest and shortest edges is 1:$$\sqrt{1-\frac{\cos\frac{\pi}{7}}{\cos\frac{2\pi}{7}}-1}$$ ≈ 1:1.84200.