28"W X 36"H [Duct Opening] Steel Air Vent Return Grille - HVAC VENT DUCT COVER DIFFUSER - [Outer Dimensions: 29.75"W X 37.75"H] sidewall with actual outer dimensions of Compatible With Duct 7in Applications This sheet metal DDAG-A-1212

with actual outer dimensions of 22

Insulation – A thick blanket of fiberglass insulation provides you with an R-Value of 4

+ Product Details Size - 10"w X 18"h is the size for the duct opening measurement only

+ Product Details Size - 4"w X 20"h is the size for the duct opening measurement only

+ Product Details Size - 20"w X 24"h is the size for the duct opening measurement only

28"W X 36"H [Duct Opening] Steel Air Vent Return Grille HVAC VENT DUCT COVER DIFFUSER [Outer Dimensions: 29.75"W X 37.75"H] sidewall with actual outer dimensions of Compatible With Duct 7in Applications This sheet metal DDAG A 1212 with actual outer dimensions of 22 Insulation – A thick blanket of fiberglass insulation provides you with an R Value of 4