12" X 4" ADJUSTABLE AIR SUPPLY DIFFUSER - HVAC Vent Duct Cover Sidewall or Ceiling Copper Coil-Insulated Line Set Some of the best features

Some of the best features aren't readily apparent

Actual Filter Size – 21 3/4"w x 29 3/4" x 1"

+ Product Details Perfect Fit & Easy Sizing - Designed for a 14" x 30" OR 30" X 14" duct opening (measured at the opening)

+ Product Details Size – 10"w X 36"h is the size for the duct opening measurement only

actual front end outer dimensions are approximately 16 5/8" width X 30 5/8" height

12" X 4" ADJUSTABLE AIR SUPPLY DIFFUSER - HVAC Vent Duct Cover Sidewall or Ceiling Copper Coil-Insulated Line Set Some of the best features+ Product Details Size 12"w X 4"h is the size for the duct opening measurement only, actual front end outer dimensions are approximately 13. 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