18" X 18" ADJUSTABLE AIR SUPPLY DIFFUSER - HVAC Vent Duct Cover Sidewall or Ceiling 12in diameter please note that the total

please note that the total outer dimensions of the grille measure 8" in diameter

actual front end outer dimensions are approximately 38 5/8" width X 18 5/8" height -

Actual Filter Size – 17 3/4"w x 15 3/4" x 1"

even without needing to remove the thermostat

18" X 18" ADJUSTABLE AIR SUPPLY DIFFUSER - HVAC Vent Duct Cover Sidewall or Ceiling 12in diameter please note that the total+ Product Details Size 18"w X 18"h is the size for the duct opening measurement only, actual front end outer dimensions are approximately 19. 875" width X 20" 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