You will need a power suppy (Wall Wort or laptop Power supply) that will provide the proper voltage, the right polarity and enough amperage to run the fan. If you plug the fan directly into the wall it will fry. The four wires on the can be described this way. One is the ground wire, one is "The Common" meaning, in this case because it's DC voltage "the negative", another (Sometimes Yellow) is used for speed control and one is the "Positive". With a cheap DC voltage meter you can makes sure you have the right ones when you hook it up to your power supply. Be carefull If you hook the positive from the power supply up to the negative of the fan it will run backwards and usually burn it out. I did this and cost me a $20.00 fan. You want your fan to run at top rated rpm. So either tape up the "speed control" wire and keep it back out the way or attach it to the "Postive' wire of the fan, which ever works. You can't hurt the fan so use the trial and error method for this part of the hook up. Hope this helps I like computer fans because their quiet. Their good for cabs and closets but not larger grows.