Each of the twelve Pentacubits is composed of five rhombi. The Pentacubits belong to the family of Polycubits.

The base unit of the Polycubits is a rhombus with interior angles of 60° and 120°. These rhombi fit seamlessly into the cubit grid shown.

There are: 1 Dicubit, 3 Tricubits, 4 Tetracubits, 12 Pentacubits, 27 Hexacubits, and 78 Heptacubits.

Shapes composed of all 12 Pentacubits cover an area of 60 rhombi. However, a fully filled equilateral triangle requires 63 rhombi. For this reason, the 3D-printed puzzle version includes one additional Tricubit.

The underlying cubit grid allows shapes with six lines of reflection and six-fold rotational symmetry. Fully symmetric shapes made solely from the 12 Pentacubits are, however, (presumably) impossible.

The puzzle was developed with support from the PolySolver program.

The 3D-print templates consist of the 12 Pentacubits and 1 Tricubits puzzle pieces and a box.