Your TV is mounted on the wall.  There is no place to run wires or to place devices attached to your TV.

Screw the mounting cleat to the wall.  Make sure the top of the cleat is even with the level line that you drew. 

(Optional Step) Install an outlet in the wall at either end of the mounting cleat.  This will provide an easy way to run power to the Hidden Wire Mantel.

Run all the wire through the Hidden Wire Mantel.  The access holes allow you to easily move the wires through the mantel.

Secure the Mantel Cap inplace with the included pre-drilled screws. 

Enjoy your new Hidden Wire Mantel.  You can now place internet boxes, game consoles, and many other device right on the Mantel.  All the wires are hidden from view.