Lambro 3-1/4 In. x 10 In. White Plastic Kitchen Wall Vent Cap with Damper

Opening/closing damper prevents outside elements from entering the vent. Damper is spring loaded to keep damper closed when not in use. UV inhibitor is used to help prevent the premature fading of vent. For 3-1/4″ x 10″ duct, with damper. For use with rigid ductwork. Plastic.