Crawl Space Recessed Foundation Vent Cover - White (For 8"x16" Foundation Openings) Crawl space vent cover recesses into most 8"x16" openings. This is a solid piece cover. It does not open. Attaches to inside of crawl space foundation opening with fasteners or adhesive (not included). You must remove you old vent to use this cover. Crawl space vent cover can be insulated by gluing insulation inside the cover. May be used permanently or just for winter. Dimensions: Rectangular Inside - 7  X 15" Outside Mounting Lip - 9  X 17 " Inside Recessed Depth - 1 ". Excellent for closed, encapsulated or conditioned crawl spaces. May be painted with a plastic adherent paint.