24" X 8" ADJUSTABLE AIR SUPPLY DIFFUSER - HVAC Vent Duct Cover Sidewall or Ceiling 6in diameter Actual Filter Size – 21

Actual Filter Size – 21 3/4"w x 5 3/4" x 1"

and with a built-in back 1/2" mesh they also protect you from annoying rodents like mice

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

actual front end outer dimensions are 19" Width X 19" Height

24" X 8" ADJUSTABLE AIR SUPPLY DIFFUSER - HVAC Vent Duct Cover Sidewall or Ceiling 6in diameter Actual Filter Size – 21+ Product Details Size 24"w X 8"h is the size for the duct opening measurement only, actual front end outer dimensions are approximately 25. 875" width X 10" 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