This reversible, two-piece cable entrance plate makes pulling wires through the wall fast and simple, and the removable lower plate means you can get all the wires connected first, then quickly cover it up.  
Arlington™ Reversible Two-Piece Low-Voltage Cable Entrance Plate
This reversible, two-piece cable entrance plate makes pulling wires through the wall fast and simple, and the removable lower plate means you can get all the wires connected first, then quickly cover it up. There's no fumbling around with a decor plate, and the angled nose on the front hides the hole in the wall. This plate can be mounted directly onto the wall with drywall screws, or you can use a double gang low voltage bracket with the supplied screws to attach the wall plate to the bracket.
Important Note - This product is designed for Low Voltage Class 2 wiring only.