Add Vulcan’s heat-reactive matrix and ember-screening technology behind a compatible existing vent opening with this nominal 48-inch by 24-inch retrofit panel. The assembly combines coated aluminum honeycomb with stainless-steel mesh to create a physical ember barrier and a matrix designed to expand under extreme heat. It is commonly used on the interior side of existing gable vents or adapted to custom openings where a complete framed vent is not the right fit. Finished NFVA depends on the opening pattern and installed assembly. Confirm whether the product will be sold as a full sheet or by linear foot, verify field dimensions, and obtain installation guidance before cutting or modifying it.