NOISE AND RAIN-PROOF: Roof ventilator fan rotates without noise. The distance between the downward protruding slats is small enough to prevent rain from entering the ventilation system. The hood is designed to rotate with the wind, so the stronger the wind, the more the blades rotate, and the greater the air intake from the inside out. How it works: the rings of the Chimney hood have been specially designed to fit one over the other so that wind cannot blow down the chimney, making this Chimney hood the perfect draught-proofing solution. Rotating hoods are suitable for ventilation ducts, extraction chimneys and air extraction. The hood provides maximum protection without hindering the performance of the chimney. STAINLESS STEEL ROTATING Chimney COVER: Thick stainless steel rotating Chimney cover, rotating and anti-sinking, suitable for most standard Chimney covers, very good windproof effect, increase ventilation Versatile: Rotating hoods for ventilation ducts, chimneys and exhaust pipes. Ties provide maximum protection without compromising the performance of the chimney. Protects chimneys from rain and moisture and is particularly suitable for chimneys that are used infrequently.