Overview：

Extruder expansion fan can effectively reduce the temperature of the extruder. 
Extruder expansion fans are beneficial for improving the print stability of filaments such as PLA, PETG and other filaments that are generally not resistant to high temperatures.

Compatibility:

 QIDI Q1 Pro 3D Printer

Installation Guide:

https://wiki.qidi3d.com/en/Q1/Manual/Extruder-fan-installation