  Black holes in a class of string compactifications, known as STU models,
carry four electric and four magnetic charges. Furthermore a duality group,
given by the product of three congruence subgroups of $SL(2,\mathbb{Z})$, acts
on these integer valued charges. By placing these eight charges at the eight
corners of a Bhargava cube, we provide a classification of the duality orbits
in these theories.
