Decagonal duoprism

The decagonal duoprism or dadip, also known as the decagonal-decagonal duoprism, the 10 duoprism or the 10-10 duoprism, is a noble uniform duoprism that consists of 20 decagonal prisms, with four at each vertex. It is also the 20-9 gyrochoron.

This polychoron can be alternated into a 5-5 duoantiprism, although it cannot be made uniform.