The Lambro 6-In. 26-Gauge Paint-Grade Galvanized Wall Exhaust Hood Vent with Damper and 11-In. Pipe is ideal for venting through the wall. It features a spring-controlled opening and closing damper that prevents outside elements and air from entering the vent. The damper seals the vent opening when the bath fan, range hood, or microwave are not running. When the appliance operates, the exhaust air pressure pushes the damper open to let the exhaust air escape from the vent. The vent is for new and replacement installations over an existing 6-in. opening. It features an opening containing the 1/4-in. wire mesh screen with a net-free area of 15 sq. in., allowing for less back pressure. When the screen is removed, the net-free area of the unrestricted opening is now 40 sq. in. Constructed from 26-gauge paint-grade steel, this vent is built for durability and long-lasting performance. Make sure to check local building codes before installation. This is not for use with clothes dryers.