Broan-NuTone 4.78 in. W X 12.75 in. L Black Steel Wall Vent

Select the Broan-NuTone 639 Wall Cap to provide reliable wall ventilation. Features a black enamel finish and is designed for use with 3-1/4″ x 10″ duct. Includes a built-in back-draft damper, and protective bird screen to prevent small pests from entering duct.Equipped with a spring-loaded backdraft damper and bird screen to keep nests and small animals on the outside,Wall cap is made of 24 gauge CRCQ steel construction with a black electrically-bonded epoxy finish for durability and long life,Not for use with dryer venting