20" X 4" ADJUSTABLE AIR SUPPLY DIFFUSER - HVAC Vent Duct Cover Sidewall or Ceiling w16h16 + Product Details Size -

+ Product Details Size - 24"w X 2"h is the size for the duct opening measurement only

+ Product Details Size – 20"w X 30"h is the size for the duct opening measurement only

+ Product Details Perfect Fit & Easy Sizing - Designed for a 10" x 20" duct opening (measured at the opening)

actual front end outer dimensions are approximately 16 5/8" width X 10 5/8" height

For 8" duct opening

20" X 4" ADJUSTABLE AIR SUPPLY DIFFUSER - HVAC Vent Duct Cover Sidewall or Ceiling w16h16 + Product Details Size -+ Product Details Size 20"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