Strut Tower Bars or Braces are designed to lay on top of your strut mounts and stiffens your car. You ask yourself how? Even though you may not be able to notice it your car's body and chassis as a whole can flex and bend. A Strut Tower bar will help stiffen up the chassis of the car.
A strut tower bar is functional and also provides for some nice eye candy whether it be in your engine bay or trunk.