WELLAND Hickory Hardwood Vent Floor Register Self Rimming Unfinished (4x12 INCH) Fits a duct size opening of 4" x 12", Overall dimension is 13.6" x 5.6" x 0.75" Made of Unfinished Solid Grade A Hickory Wood Self-rimming (drop-in) installation, louvered design Also known as insert vent Authentic WELLAND Product Made of two parts ,Easy to install Self-rimming (Drop-in) installation Louvered design insert vent Fits a duct size opening of 4&#034; x 12&#034; overall dimension is 13.6&#034; x 5.6&#034; x 0.75&#034; 3/4&#034; Thickness Beautiful and High Quality. Authentic WELLAND product Measure the size of the duct opening. Do not measure your current floor register. Fits a duct size opening of: 4&#034; x 12&#034; you must measure the size of the duct opening