Elongated pentagonal bipyramid

In geometry, the elongated pentagonal bipyramid or pentakis pentagonal prism is one of the Johnson solids (J16). As the name suggests, it can be constructed by elongating a pentagonal bipyramid (J13) by inserting a pentagonal prism between its congruent halves.

A Johnson solid is one of 92 strictly convex polyhedra that is composed of regular polygon faces but are not uniform polyhedra (that is, they are not Platonic solids, Archimedean solids, prisms, or antiprisms). They were named by Norman Johnson, who first listed these polyhedra in 1966.[1]