1.No power ventilation fan use natural wind driven or air heat convection caused by Indoor and outdoor temperature difference to push turbine run, then exhaust the indoor not fresh air by centrifugal force and negative pressure.

2.Curved blades are the best results of scientific calculation and it can ensure no rainwater intrusion.

3.Unique variable angle tube suit for any industry workshop, poultry farm, high building,residential houses etc. Better improve work environment and enhance work quality and efficiency.

4.Nature wind drives,operating in 24hs the whole day. Environmental protection, energy saving and no electricity cost.