DC 12V Single PWM Speed Controller Fan Speed Controller 4 Pin Switch for PC Fan

Description

If you want to control a 12VDC four wire fan, this is what you need!
By rotating the potentiometer, the fan speed can be easily adjusted.
The PWM frequency is 25KHZ, which can adapt to most 12V adjustable speed fans on the market.  The duty cycle can be adjusted from 0% to 97%, and the speed regulation range is wide.  Rotary potentiometer with switch, easy to start and stop (has an OFF position).
Input voltage: 12VDC.  The negative wire hooks to pin 1, the positive wire hooks to pin 2.  Pin 3 is not used.  Please see last picture (the piece of equipment with the fan is for demonstration purposes ONLY and is NOT included).
The size of the circuit board is 0.98" x 0.79".