8" x 4" ADJUSTABLE AIR SUPPLY DIFFUSER - HVAC Vent Duct Cover Sidewall or Ceiling Grilles + Product Details Size –

+ Product Details Size – 20"w X 28"h is the size for the duct opening measurement only

Actual Filter Size – 31 3/4"w x 13 3/4" x 1"

This Will Create A Cycle Of In And Out Air FLow

The crank handle lever makes it easy to adjust to every weather situation

Actual Filter Size – 9 3/4"w x 33 3/4" x 1"

8" x 4" ADJUSTABLE AIR SUPPLY DIFFUSER - HVAC Vent Duct Cover Sidewall or Ceiling Grilles + Product Details Size –+ Product Details Size 8"w X 4"h is the size for the duct opening measurement only, actual front end outer dimensions are approximately 9. 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