The Lambro 4-In. Brown Plastic Exhaust Louvered Vent is ideal for venting through the wall. The vent features opening and closing flaps that seal the vent opening when the clothes dryer or bath fan is not running because no exhaust air exits the vent. When the fan operates, the exhaust air pressure pushes the flaps open to let the exhaust air escape from the vent. You can easily use the exhaust vent for new and replacement installations over an existing 4-in. opening. The vent frame comes with 4 screw holes to secure the vent and a caulk-friendly frame for completing the installation. The vent is a low-profile design that only protrudes a half in. from the side wall when installed. The vent features an opening when the flaps open; the net-free area of the opening is 9.9 sq. in. It is crucial to check the inside of the vent regularly to prevent lint build-up when using it to exhaust a clothes dryer. The vent's manufacturing material is polymer resin with a UV additive to prevent premature fading caused by sunlight. It would be best to prep the vent before painting; a plastic paint is recommended for effective painting. Make sure to check local building codes before installation.