16 in. x 25 in. Return Air Box with Filter Rail

Take advantage of the durable 30-gauge zinc-coated, galvanized steel construction of this Master Flow 16 in. x 25 in. Return Air Box to equip your HVAC system with a long-lasting air return box. Its 16 in. x 25 in. opening acts as a convenient connection from return fittings to a ceiling or wall grill (not included) for return air needs. Cut your own opening and install a collar (not included)up to 16 in. diameter to attach pipe or flexible duct as needed.