An automatic replacement foundation vent designed to replace manual vents, suitable for standard 8x16 in. vent openings in crawl spaces. It uses a bi-metallic coil enclosed in a protective cover, which automatically opens at approximately 70°F and closes at around 40°F without needing electricity. This ensures effective ventilation, promoting air circulation in the crawl space. With 57 square inches of net free ventilating area, it helps maintain a healthy environment. Constructed with high-density polyethylene, stainless steel compression spring, and heavy-duty aluminum parts, it offers durability and corrosion resistance. The design helps save energy by preventing unnecessary air loss and reduces the risk of frozen pipes, while also helping to prevent foundation decay. Color: Black. Material: Plastic.