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 actual front end outer dimensions Compatible With Duct 7in Applications This sheet metal DDAG-A-1212

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

and then smoothly drop in the grill

actual front end outer dimensions are approximately 24 5/8" width X 14 5/8" height

Its lightweight aluminum construction guarantees long-lasting performance

Actual Front End Outer Dimensions Are 11

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 actual front end outer dimensions Compatible With Duct 7in Applications This sheet metal DDAG A 1212 actual front end outer dimensions are approximately 22 5 8" width X 16 5 8" height and then smoothly drop in the grill