JYINCPED Galvanized Steel Hooded Wall Vent with Screen and Damper for Air Exhaust and Prevent Insect Out Wall Vent Duct Diameter: 7 inch Wall Vent Duct length: 8-1/4 inch Long enough for wall mounted installation and easily connect to solid metal pipe or flexible ducting hose Spring loaded backdraft damperwith Foam Gasket The outdoor vent hood damper open to allow the air exhaust, even at low fan speeds The outside vent cover damper stay closed when not work to prevent outside air backflow or insects from coming inside the home The foam gasket on the wall vent cover damper reduce noise and provide quiet operation even on windy days Steel Mesh Screen The vent hood screen keeps rodents, birds, insects and squirrels out The wall vent cover rivets secure the mesh screen to ensure no-gap connection to the vent cap and not pop it out of the way Galvanized Steel hooded Vent Cap The wall vent cap constructed from high-quality 28 gauge galvanized steel featuring rust-proof, anti-corrosion and withstand extreme condition Easy to Install No need to drill holes Wall mount vent cover comes with 4 pre-drilled holes on the flange and 6 screws to easily be attached by using screw in each corner Vent hood wall cap comes with a aluminum foil tape used to fix and seal the vent pipe connection for max ventilation efficiency and prevent water leakage & air leakage