Widely used in homes, offices, shops, hospitals and hotels and other places. Super quiet, durable, stylish, large air volume, super quiet. Space dedicated exclusively used by the U.S. oil, closed gear box design, to create a real "only the wind, no sound" large air volume, speed readily. Perfect aerodynamics, only three blades that reach large amount of wind. The first was China's "state inspection", the strict process inspection of more than 100 product manufacturing process, to ensure safe use. Durable, value for money.