203.2-mm Height × 406.4-mm Width Crawl Space Flood Vent: The flood vent features zinc-coated steel and surface paint treatment to resist corrosion and damage from impact. Adding the crawl space flood vent to foundation walls provides a means that permit the automatic entry and exit of floodwaters which protects your foundation and reduces your flood risk. It may lead to a much lower insurance premium for your home. This foundation flood vent is surface mounted over the foundation opening and is usable in crawl spaces, garages, and full-height enclosures.