10" X 4" Adjustable AIR Supply Diffuser - HVAC Vent Cover Sidewall or Ceiling - Grille Register - High Airflow - Black [Outer Dimensions: 11.75" w X 5.75" h]

10" x 4" adjustable air supply diffuser - HVAC vent cover sidewall or ceiling - grille register - high airflow - black [outer dimensions: 11.75"w x 5.75"h] 10"w x 4"h is the size for the duct opening measurement only. The actual front end frame outer dimensions are 11.75"w x 5.75"h - see below in description how to measure a grille. You may think of grilles and registers as a generic component of the ventilation system in your house. But they are also the most visible representation of your air system. These grilles and registers give you an extra measure of quality that you can point out to your family members and house guests. Some of our best features aren't readily apparent, but you'll appreciate the benefits over a long period of time. This grille has a high standard of design, production, and finish on all products. Every part is hand inspected for quality before it is packaged, no exceptions. Quality packaging - carefully shrink-wrapped with cardboard backing to prevent damage in shipment. Easy unrestricted air flow. How to measure a grille: Overall Size: Measure the size of the air duct/drywall opening. Do not measure the overall size of the register itself, only measure the "hole" in the wall/duct. Every grille has a front end frame that will overlap at the wall joint. Total outer size of this grille is; listed size + 1.875" at the width, and + 2" at the height. Width vs Height: The first number in a grille size represents the width, the second number represents the height. Example: If your hole is 20" wide by 14" tall, order a 20x14. If your hole is 14" wide by 20" tall, order a 14x20.