12" X 6" [Duct Opening] 3-Way Air Vent Adjustable Aluminum Curved Blades Integral Multi-Shutter Damper HVAC Diffuser [Outer Dimensions: 13.75"W X 7.75"H] white + Product Details Size - 4 X 12 Is CRFG2028 Width_14in

+ Product Details Size - 25"w X 10"h is the size for the duct opening measurement only

2" X 10" Brass Victorian Floor Register Grille - Modern Contempo Decorative Grate - HVAC Vent Duct Cover - Brass Plated

+ Product Details Size – 12" x 24" or 24" x 12" is the size for the duct opening measurement only

4" X 12" Is The Size For The Duct Opening (floor/vent hole) Measurement Only

actual front end outer dimensions are approximately 18 5/8" width X 36 5/8" height

12" X 6" [Duct Opening] 3 Way Air Vent Adjustable Aluminum Curved Blades Integral Multi Shutter Damper HVAC Diffuser [Outer Dimensions: 13.75"W X 7.75"H] white + Product Details Size 4 X 12 Is CRFG2028 Width_14in + Product Details Size 25"w X 10"h is the size for the duct opening measurement only 2" X 10" Brass Victorian Floor Register Grille Modern Contempo Decorative Grate HVAC Vent Duct Cover Brass Plated