Nope. That's not a brake controller.
This is a brake controller:
http://www.etrailer.com/dept.aspx?fu...FTRn7Aod-h4Ajw
The purpose of said brake controller is to be able to adjust the brakes on the trailer.
If you're pulling a heavy load, you can increase the brake power of the trailer, to that the TRAILER is stopping you, and you're not getting pushed by the trailer and burning up your brakes.
Only works if you have a trailer with brakes, but it's pretty damn nice thing to have.
Had a buddy with a old F250 he would pull a dump trailer with. The trailer brakes stopped the truck, and the trailer more than the truck stopped the truck and trailer.
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"We are experts in the application of violence."
-LtCol Christian Cabannis, Camp Letherneck, Afghanistan, 2009. The "Summer of Decision."