  In this short note, quantum subgroups in finite free products of the
Pontryagin duals of free unitary quantum groups are classified. They correspond
to pairs of a subgroup $\Gamma$ and a subset $S$ of the free group
$\mathbb{F}_n$ such that $S$ is $\Gamma$-invariant, containing $\Gamma$, and
connected in the Cayley graph of $\mathbb{F}_n$
