Passive Inlet Vents bring outside air into the house to balance indoor/outdoor air pressure in tight houses. The passive inlet vent flows air into the house when the pressure inside is lower than the pressure outside. Passive inlet vents operate with 2-position air delivery on three speeds: closed, 12 CFM and 18 CFM. Equipped with a washable air filter, a bug screen, a foam pad for reducing outdoor noise and condensation, and an insulation lining to prevent condensation, the passive inlet vent features a 3" diameter and a 12" long through-the-wall sleeve. KitchenSource.com features a wide selection of bathroom and home ventilation products from top brands, like Panasonic, Broan, Air King, AUPU and Fantech.