Zinc-efflux transporter which allocates the cytoplasmic zinc to the trans-Golgi network (TGN) as well as the vesicular compartment. Heterooligomer. Interacts with ZNT5 (By similarity). Found in vesicles. Expressed in brain and liver, and to a lower extent also in lung. Highly expressed in brain (at protein level). Seems to have lost most of the histidine residues in the loop between the fourth and fifth transmembrane regions and appears to exert transport function by forming complexes with ZNT5. Belongs to the cation diffusion facilitator (CDF) transporter (TC 2.A.4) family. SLC30A subfamily.