Vent louver ND12Z by Europlast, in a square shape. The louver is used in ventilation systems so that indoor air can be expelled into the environment. This helps keep your space clean, free from odors and harmful particles. It is gravity-operated, which means that its slats open only when the ventilation system is running. When the airflow stops, they close and prevent the entry of outside air. Additionally, it features a protective mesh to prevent insects from entering during its operation.