... forming. Large air volume, no deformation, no broken, no dust, attractive and durable. Thickness 1.2mm, surface finish BA grade ... into the poultry farm house. As the first one adopt high quality nylon PA66 to ensure the long service life. The fasteners ... bearing with special waterproof design, water can’t enter. High strength, lower noise, maintenance free and long service life. exhaust fan from Yihe