MAGR4 Select 4" x 10" Maple Grill Unfinished (Drop in) Standard Vent- Surface Mount GrillSelf-rimming or an Overlap insert mount ventThis style fits over any existing or new duct opening. Gently rounded lip conceals rough floor edges. Adds a finishing touch to any floor- wood, stone, tile, vinyl or carpet.-Used with any floor thickness.-Easy to install- simply drop the unit into the duct opening.-Optional metal damper allows personalized airflow regulation.See our article on Hardwood Grill/Vent covers in Flooring 101 for information on measurement.