This is an antique or vintage heavy solid brass mail slot with matching inside trim part. The slot is spring loaded to keep it closed. Some corrosion to spring mechanism. Both the outside slot and trim piece have an egg-and-dart motif around edges. The inside piece appears to have a Japanned finish. The outside slot has very heavy oxidation (some of which was buffed off to highlight lettering). This item was made by the Sargent and Company in Connecticut, probably in the 1920s or 30s. Both outer and inner parts have same dimensions: 6 1/4 by 2 1/2 inches. Opening is 4 3/4 by 1 1/8 inches.