If this is a replacement, lift out the old vent cover. If you're working on a new constructions, proceed directly to Step 2.
Measure the opening in your floor, wall or ceiling. The width and length of your opening should match the width and length of the inside measurements of the grille.
Please measure again to ensure correct measurements.
Go to the product page of your choice (metal, wood, etc.). Choose the option that best fits your needs than choose the inside measurement that matches the width and length of your inside opening.