Get this Broan-Nutone 3 in. to 4 in. Roof Vent Kit for Round Duct Steel – Black for delivery. Built-in backdraft damper prevents outside air from entering home. Built-in bird screen prevents birds and other small animals from entering duct work. Kit includes all materials needed for install: 8 ft. of 4″ flexible ducting, 4″ metal duct connector, 4″ to 3″ Reducer, nylon zip ties and mounting screws. Constructed of durable, resilient steel with a black powder coat finish. Easy to install in new construction, replacement, or DIY applications. Compatible with 3″ and 4″ round ducting. Not suitable for dryer venting or flat roofs.

Get this Broan-Nutone 3 in. to 4 in. Roof Vent Kit for Round Duct Steel - Black for delivery. Built-in backdraft damper prevents outside air from entering home. Built-in bird screen prevents birds and other small animals from entering duct work. Kit includes all materials needed for install: 8 ft. of 4" flexible ducting, 4" metal duct connector, 4" to 3" Reducer, nylon zip ties and mounting screws. Constructed of durable, resilient steel with a black powder coat finish. Easy to install in new construction, replacement, or DIY applications. Compatible with 3" and 4" round ducting. Not suitable for dryer venting or flat roofs.