18" X 4" ADJUSTABLE AIR SUPPLY DIFFUSER - HVAC Vent Duct Cover Sidewall or Ceiling Compatible With Duct 10in But they are also the

But they are also the most visible representation of you air system

The total outer size of this grille is the listed size plus plus 2 and 5/8"

+Why Hvac Premium HVAC Premium has been providing superior quality service for many years

Actual Filter Size – 13 3/4"w x 24 3/4" x 1"

18" X 4" ADJUSTABLE AIR SUPPLY DIFFUSER - HVAC Vent Duct Cover Sidewall or Ceiling Compatible With Duct 10in But they are also the+ Product Details Size 18"w X 4"h is the size for the duct opening measurement only, actual front end outer dimensions are approximately 19. 875" width X 6" height. High Quality High quality steel construction, no scuff powder coat durable finish, smooth, shiny, scratch resistant, no sharp edges, 2 recessed screw holes on each side with screws included, screws same color as vent cover, easy installation. Adjustable airflow control Adjustable airflow