How To Measure a Grille Measure the size of the air duct/drywall opening.DO NOT MEASURE the overall size of the register itselfOnly MEASURE the "HOLE" in the wall/duct. Every grille has a front end frame, that will overlap at wall joint.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. Fixed Hinged Steel Return Filter Grille - Ceiling Recommended Easy to Open and Close Requires No Screwdriver To Open After Installation, Just Open and Close Latches to replace filter. Fixed Hinged This model has fixed hinges so that you cannot completely remove the door for safety. Perfect for ceilings. This fixed hinged steel return filter grille model has ½” fin design. Total outer size of this grille is; listed width + 2.5", listed height + 1.75". 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 are visible to your family members and house guests. High Standard Every part is hand inspected for quality before it is packaged, no exceptions. No Sharp Surface Edges. Just run your finger along the edge of the top plate and you will find a smooth finished surface. Powder-Coat Finish - Smooth, Shiny, Scratch-Resistant, Beautiful.