High-quality stainless steel material, non-energy power fan, strength enough to withstand 200 km/h wind speed, 100KG load capacity, heavy pressure without damage or deformation. The galvanized bearings are designed to be enlarged and thickened, which has a stronger bearing capacity, and rotates silently without producing more sound, which is very suitable for garden roofs, public baths, etc. It has a wide range of applications, which is very suitable for farms, breeding farms, industrial plants, cargo warehouses, chimney tops, and is used without electricity, reducing more trouble. No electricity, no maintenance, no electricity, automatic exhaust throughout the day will also reduce the occurrence of fires and a lot of other unnecessary troubles caused by short circuits or voltage overloads for you. Smooth surface, smooth and beautiful appearance, the overall design is unique and eye-catching, and is deeply loved by the public. Roof exhaust fan, no electricity, wind exhaust fan, is very simple and easy to install exhaust fan, very suitable for garden house, factory, farm, farm and other places.✔ Specification: Product name: There are no power ventsApplicable objects: household/commercial Material: stainless steel Size: 110mm/4 1/3inch , 160mm/6 1/3inch , 200mm/8inch , 250mm/10inch , 300mm/12inch , 350mm/14inch , 400mm/16inch , 450mm/18inch , 500mm/20inch , 600mm/24inch , 800mm/32inch Prompt.○ This product contains only stainless steel vents and does not contain any of the products shown in the figure.○ This product is measured by hand, please allow an error of 1-3 cm, please confirm that you don't mind before placing an order.○ The product is genuine, but due to factors such as shooting angle, light, display parameters, etc., the actual color may be different from the photo, and the actual product shall prevail.