7-2 step prismatic alterprism

The 7-2 step prismatic alterprism is a convex isogonal polyteron that consists of 2 7-2 step prisms, 14 bilaterally-symmetric triangular duotegums, and 42 bilaterally-symmetric pentachora of three kinds. 1 7-2 step prism, 6 bilaterally-symmetric triangular duotegums, and 15 bilaterally-symmetric pentachora join at each vertex. However, it cannot be made uniform.

Using the ratio method, the lowest possible ratio between the longest and shortest edges is 1:$$\sqrt{2\cos\frac\pi7}$$ ≈ 1:1.34236.