Product Description Lambro's low-profile design of the louvered vent allows for maximum exhaust airflow when venting a clothes dryer or bathroom fan. The louvers open and close quietly while air is flowing through the vent. This vent can be used in other 4 in. exhaust venting applications. From the Manufacturer Lambro 4 Inch White Plastic Louvered Vent w/ Tail Pipe is manufactured in by Lambro in the USA. Many products can be used in other areas of the home and are easy to use and install.