Roof vent kit for complete roof ducting installation of exhaust fans with 3-inch or 4-inch duct connector. Kit includes: Black steel roof cap with built-in back draft damper and bird screen, 4-inch diameter metal duct connector, 2 nylon zip ties, 3-inch to 4-inch duct adapter, 8 feet of 4-inch diameter flexible foil ducting (conforms to UL181 Class 1 air connector requirements). Also includes neoprene foam strip which can be used to increase duct diameter if attaching to fan with 3-inch duct collar. Not recommended for dryer or range hood venting.