20" x 4" x 12", Foundation Vent Well, Is Used To Provide Adequate Space For Foundation Vents, This Foundation Vent Well Is 20"W x 4" Projection Distance Away From Wall x 12"H, These Wells Are Formed From Steel To Provide Long Lasting Durability, Each Foundation Vent Well Provides Enough Area For Crawl Spaces & To Keep Dirt Away From Foundation To Allow Air Flow Through Vent, This Allows Access To Foundation & Prevents Moisture Build Up.