Variable angle neck design: The exhaust fan can be installed on a slope of 0-22.5 degrees as required. Zinc-plated bearings are strong enough to withstand 200km/h wind speed and 100KG load pressure without deformation or damage. Product Material: The Roof Wind Smoke Evacuator is made of 304 stainless steel, which is thick, wear-resistant and hard. It will not be deformed even if it is subjected to a weight of 100 kilograms. The galvanized rollers are flexible, durable and pressure-resistant. Position the stainless steel roof wind turbine vent cover on the roof to achieve optimal airflow. Then ensure the vent is securely fastened to the roof to prevent any leaks. Hood size:4.3inch(110mm), 6.3inch(160mm), 7.9inch(200mm), 9.8inch(250mm), 11.8inch(300mm), 15.7inch(400mm) It efficiently removes stale air from the room whilst preventing rainwater from entering the ventilation system., Manufacturer: YKMYXZ