Deltana CPC4764 Switch Plate, Cable Cover Plate, Solid Brass

That is exactly what a cable cover plate does. The CPC4764 has a solid face with a cable pass-through rather than a toggle or duplex cutout, so it covers a one-gang box cleanly and lets low-voltage or AV cable exit the wall. It measures 4-1/2" x 2-3/4". If the box still holds a live device, you need a plate cut for that device instead; this one is not a blank and not a switch plate.

Solid brass, both the material and the substrate on the CPC4764 are brass, so the finish sits on brass rather than on steel or zinc. That matters in a coastal or high-humidity building, and it means the plate holds up to being taken off and put back on during repaint cycles without a plated shell wearing through at the screw holes.

Nine finishes: PVD Polished Brass, Polished Brass, Antique Brass, Oil Rubbed Bronze, Brushed Nickel, Antique Nickel, Polished Chrome, Brushed Chrome, and Paint Black. Deltana runs the same finish names across its door hardware, so if the levers and hinges in the building are Oil Rubbed Bronze or Brushed Nickel, the cable plate can be specified to match. PVD Polished Brass is the one to pick if you want polished brass that will not need lacquer touch-up in a heavily handled location.

Commercial. Deltana classes the CPC4764 as a commercial product, and it is solid brass rather than stamped steel or plastic, which is what makes it hold up in a hotel corridor, an office fit-out, or multi-family common area where plates get knocked and cleaned constantly.