The main cufflink's shape is composed by a cube, a sphere and an elliptic toroid, all modelled by implicit equations. Particularly, for this model the cube sides measure exactly 4 x Pi [mm].
To reduce Weight and Costs, the cube and sphere were hollowed out without affecting the overall look and feel.
The "filling" is a surface normally called a Gyroid, a surface that has these properties:
It is periodic in all three axes [Triply Periodic].
It is a minimal surface, which means it has a minimum area for it's boundary perimeter. Just like a soap bubble.
It is non-trivial, unlike a plane or a sphere (which are also minimal surfaces). (Pff!! totally evident)
It splits the space into two, completely identical labyrinths.
For some strange reason, if a psychologist asked me to say the first thing that comes to my mind when seeing a Gyroid (Associative Test), I would probably say Lasagna!!!