Two important indicators of general "Mini Air Cooling Fan" shake test is: frequency swivel and twist angle. GB Requirements: 4≤ twist frequency ≦ 7, swivel angle ≥60 ° swivel so you can know the frequency is not the better, nor is it as small as possible, while the swivel angle is better. General brand landing "Mini Air Cooling Fan" about shaking his head at an angle of 60 to 90 degrees, the pitch angle of 30 degrees; there are also some professional brand shaking his head angle up to 120 degrees, tilt angle of nearly 45 degrees. Shake control: the way around, shaking his head and has a plug-in electronic, mechanical stand fan / desk fan / Desk Stand Fan commonly used gearbox pluggable, fan page using switching control; remote stand fan / desk fan / desk stand. " Mini Air Cooling Fan"synchronous motor electronic; pat down the pitch into one style and lock nut fixed;