Ordinary fans can only provide efficient cooling to a flat surface while we make the air flow following the shape of the motor and force the wind to get in the motor to achieve the maximum cooling. Ordinary fans can only generate about 2 gram around on a motor shape but we can generate 12 gram+ wind force. Combine with our 40mm fan to generate 12g+ wind pressure without stalling and fan wind pressure drop, by far the most sufficient device for motor cooling.