Vent louver by Mmotors, in a square shape. The louver is used in ventilation systems so that the indoor air can be expelled into the environment. This way, your space can remain clean, without the presence of odors and harmful particles. It is gravity-operated, which means that the slats open only when the ventilation system is in operation. When the airflow stops, they close and do not allow the entry of outside air or insects.