A. The bearing form of the fan, the ball is still oily.
B. Determine whether the fan is DC or AC or axial.
C. What is the noise of the fan?
D. The value of the supply voltage of the fan. For example: AC 220V, 110V, 380V. DC 5V, 12V, 24V, 36V, 48V.
E. The air volume, air pressure and speed of the fan. For example, how many cubic meters per minute, or how many cubic feet per minute.
F. The general size of the fan.
