Grill with a flange and (4) screws to hold it in the foundation opening, has no flap or slide mechanism to open or close it, so the air can constantly move through. SKU: 42905918 MFG: 510WH Shop more products by Bestvents. SHARE Share on Facebook Tweet on Twitter Share on Google+ Pin on Pinterest Free shipping over $35 $10.85 Quantity In Stock Add to cart Request a Bulk Quote Thank you for your quote request. We will be in touch. DETAILS Description DESCRIPTION Highlights: Color: White Material: Polypropylene Depth: 7-3/4 inch Height: 8.5 inch Width: 15-1/4 inch Rough Opening Size: 8-inch L x 16-inch W Suitable for standard block foundation opening FEATURES MFR: 510WH SKU: 42905918 UPC: 008661510043 Brand: Bestvents