... Light weight, high revolving sensitivity, strong corrosion resistance, high air venting efficiency, clean and smooth, uniform color, and easy maintenance ... 22.5°oblique angle.Warranty: 15 yearsTask: used on the roof of acid-washing workshop, coking factory, Lampblack workshop, plating ... to exhaust the dirty and unhealthy air and bring you the clean and fresh air.New type ventilator, fluorine carbon ...