20" X 16" ADJUSTABLE AIR SUPPLY DIFFUSER - HVAC Vent Duct Cover Sidewall or Ceiling ceiling + Product Details Size -

+ Product Details Size - 18"w X 12"h is the size for the duct opening measurement only

actual front end outer dimensions are approximately 14 5/8" width X 20 5/8" height -

With a 8" diameter for the duct opening measurement

875" width X 21

20" X 16" ADJUSTABLE AIR SUPPLY DIFFUSER - HVAC Vent Duct Cover Sidewall or Ceiling ceiling + Product Details Size -+ Product Details Size 20"w X 16"h is the size for the duct opening measurement only, actual front end outer dimensions are approximately 19. 875" width X 18" 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