20" X 20" ADJUSTABLE AIR SUPPLY DIFFUSER - HVAC Vent Duct Cover Sidewall or Ceiling 8" Diameter + Product Details Size -

+ Product Details Size - 16"w X 28"h is the size for the duct opening measurement only

Actual Filter Size – 27 3/4"w x 19 3/4" x 1"

This grill comes in four different designs

Heavy-gauge all-steel construction

+ Product Details Size – 20"w X 24"h is the size for the duct opening measurement only

20" X 20" ADJUSTABLE AIR SUPPLY DIFFUSER - HVAC Vent Duct Cover Sidewall or Ceiling 8" Diameter + Product Details Size -+ Product Details Size 20"w X 20"h is the size for the duct opening measurement only, actual front end outer dimensions are approximately 21. 875" width X 22" 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