HVAC (heating, ventilation, and air conditioning) Stainless Steel Mushroom round roof vent cap.
The frame & blades are high quality stainless steel construction with advantages of corrosion resistance and rigidity. It is is commonly used as exhausted outlet and ventilation on the exterior walls of washrooms, kitchens, warehouses, houses,apartments, condominiums, gymnasiums...ect.
There are inverted spring hooks located on the neck , which are used to secure the device onto the wall or duct. There is air filter inserted.