Features:

CCMFC DC Motor Speed Controller provides variable speed capability for brush or brushless DC fans, or the fans without control line.
Input voltage: 12VDC
Suitable for the DC fan within 1A, Peak current 2A.
Low noise, small size.

Operating instruction:

Before you attempting to wire the controller, make sure power is off.
WARNING: DO NOT REVERSE POSTIVE AND NEGATIVE POWER LOADS AND DC FAN.THIS WILL DAMAGE THE CONTROLLER.
1.Connect wires refer to the product wiring diagram.(No.4 picture)
(Red wire connects the positive power; black wire connects negative power; white wire connects the positive of fan; green wire connects the negative of fan.) 
2. Turn on the power, and adjust the potentiometer.

Package Including:

1 x DC Motor Speed Controller
1 x button switch (a gift free)