Naiture 8" x 10" Oversized Solid Brass Floor Register Antique Style Brushed Nickel Finish Duct opening size: 8" x 10" (9-3/4" x 11-3/8" Overall) Made of heavy-duty solid cast brass for durability. Finished with a durable brushed nickel powder coat finish to resist rust. Louver control extension from register: 3/4" which could control air flow easily by foot. To determine size needed, measure air duct opening rather than old register or grille.