12"W X 30"H [Duct Opening] Steel Air Vent Return Grille - HVAC VENT DUCT COVER DIFFUSER - [Outer Dimensions: 13.75"W X 31.75"H] 10in diameter + Product Details Perfect Fit CRFG2028 Width_14in 4 X 12 Is

+ Product Details Perfect Fit & Easy Sizing - Designed for a 10" x 24" or 24" x 10" duct opening (measured at the opening)

+ Product Details Size – 12" x 28" or 28" x 12" is the size for the duct opening measurement only

actual front end outer dimensions are approximately 22 5/8" width X 16 5/8" height

Its lightweight aluminum construction guarantees long-lasting performance

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

12"W X 30"H [Duct Opening] Steel Air Vent Return Grille HVAC VENT DUCT COVER DIFFUSER [Outer Dimensions: 13.75"W X 31.75"H] 10in diameter + Product Details Perfect Fit CRFG2028 Width_14in 4 X 12 Is + Product Details Perfect Fit & Easy Sizing Designed for a 10" x 24" or 24" x 10" duct opening (measured at the opening) + Product Details Size – 12" x 28" or 28" x 12" is the size for the duct opening measurement only