![Reducer, 6 to 4](http://goodgrow.com/cdn/shop/products/ACR0604_1_{width}x.jpg?v=1632655181)
These galvanized duct reducers can be used with fans, ducting, air-cooled hoods, and ventilation systems. They allow you to connect two sides of different diameters (for example, mating ducting of one diameter to an inline fan of a different diameter).