Choose Select brand good "Inflatable Air Blower" means choosing quality from the brand, so that the DC fan is important to guarantee the quality. Select bearing up because the two ball bearings and bearing into the bearing oil. Ball bearing long life, low noise, but the price is very expensive requirements. Oil-bearing ball bearing service life is shorter than 1/3, "Inflatable Air Blower" may be some noise (over one year) in use for some time, but the price is cheap. After more understanding since we can choose, but if any ball fan and oil prices "Inflatable Air Blower" the price is almost the case, indicating that the ball bearings or the elimination of the old product, do not buy. And push for new manufacturers of bearings (except clear that the oil-bearing outer) will not exceed the life of the ball bearing, and there will be noise in the future use.