Tjernlund 950-8303 UnderAire Steel Crawl Space Vent, Morning Star Pattern, 18" x 10" Screen (Vent Screen Only) Sturdy Galvanized Steel Construction Increases Product Durability and Lifespan Install from Outside or Inside of Crawl Space 18" x 10" to Cover Block Foundation Wall Openings Professional Modern Decorative Designs with Over 80% Open Area Mounting Hardware Included