  Motivated by the dual standard model, we study the angular momentum spectrum
of stable SU(5) dyons that can be transformed into purely electric states by a
suitable duality rotation i.e. are dualizable. The problem reduces to solving a
Diophantine equation for the holomorphic charges in each topological sector,
but the solutions also have to satisfy certain constraints. We show that these
equations can be solved and sets of dualizable, half-integer spin SU(5) dyons
can be found, each of which corresponds to a single family of the standard
model fermions. We then find two predictions of the dual standard model. First,
the family of half-integer spin, dualizable dyons is accompanied by a set of
dualizable, integer-spin partner states. Secondly, the dyon corresponding to
the electron must necessarily contain non-trivial color internal structure. In
addition, we provide other general results regarding the spectrum of dualizable
dyons and their novel properties, and extend the stability analysis of SU(5)
monopoles used in the dual standard model so far to discuss the stability of
the half-integer spin dyons.
