Broan-Nutone 3-1/4 In. x 10 In. Black Galvanized Steel Wall Vent Cap

For 3-1/4" x 10" duct. Spring-loaded back draft damper and bird screen keeps out unwanted outside air and critters. Galvanized steel. Baked enamel, black finish for durability and long life that stands up to the elements. Not for use with dryers.