Vent grilles are designed for ventilation outside the building. Correctly working air circulation is required for people and animals for breathing fresh air. It is especially important in buildings with chemicals or cigarette smoke.Specifications: - Size: 150mmx150mm; - Pipe diameter: 100mm; - Anti-insect net; - Does not have a frame - possibility of covering vetilation opening of any size; - Outside hole assembly by pins, glue and silicone.