Pentagonal duoantiprism

The pentagonal duoantiprism, also known as the pentagonal-pentagonal duoantiprism, the 5 duoantiprism or the 5-5 duoantiprism, is a convex isogonal polychoron that consists of 20 pentagonal antiprisms and 50 tetragonal disphenoids obtained through the process of alternating the decagonal duoprism. However, it cannot be made uniform. Together with its dual, it is the first in an infinite family of pentagonal antiprismatic swirlchora.

Using the ratio method, the lowest possible ratio between the longest and shortest edges is 1:$\sqrt{5+√5}$/2 ≈ 1:1.34500.