WIDE APPLICATION: The louvered vent cover is perfect for 4/5/6inch vent hose, which allows for maximum exhaust airflow when venting. And perfect for bathroom vents, air conditioning units, kitchen fans & extractors, heat transfer and ventilation systems, gas & electric dryers, cooker hood extractors and all home wall vents, as well as a wide variety of industrial uses EASY TO INSTALL: In order to make the installation easier, we have equipped each vent cover with 4 screws. Just inserting the vent hose into the louvered vent cover, then you only need to mount it with screws and silicon seal. You can also use a marker to record the positions of the 4 screw holes according to the size of the ventilation cover, and use an electric drill to drill the holes. Just minutes to do that, also easy to remove and clean Stainless Steel Material: The exterior wall vent hood is made of 304 stainless steel material, , anti-rust and corrosion resistant. Automatically open and close thru blow:The air