  We consider 3d N=2 non-abelian Hanany-Witten brane setups with chiral flavor
symmetry. We propose that the associated field theories are quivers with
improved bifundamentals, instead of standard bifundamentals. The improved
bifundamental is a strongly coupled SCFT that carries one more U(1) global
symmetry than the standard bifundamental. As a consequence, our proposal
overcomes the long standing challenge of associating to each N=2 brane setup a
gauge theory with the full rank global symmetry, allowing the study of all the
usual supersymmetric observables, such as superconformal index, sphere
partition function, chiral ring and moduli space. The construction passes many
non-trivial tests, for instance we algorithmically prove that any two improved
quivers associated to S-dual brane setups are infrared dual. The 3d N=2 mirror
dualities can be uplifted to 4d dualities with 4d improved bifundamentals
connecting USp(2N) nodes.
