Specialty vent covers
These vent covers are cast of either bronze or aluminum. Bronze pieces are hand patinated, and the aluminum pieces are painted in several colors.
The 42nd street design is high style art deco, Bamboo Trellis is an Asian motif, and Wine Cellar is often specified for use in (surprise) wine cellars. Custom sizes are possible, but it pricy since it involves making new casting molds. Best to avoid that if possible.