SH Naiture 8" x 8" Solid Brass Louvered Oversized Floor Register with Damper or Lever Victorian Style, Oil Rubbed Bronze Finish Duct opening size: 8" x 8" (Overall size: 9-5/8" x 9-7/8") Made of heavy-duty solid cast brass for durability. Finished with a durable oil rubbed bronze powder coat finish to resist rust. Removable louvers. Louver control extension from register: 3/8" which could control air flow easily by foot. To determine size needed, measure air duct opening rather than old register or grille.