25" X 12" Steel Return Air Filter Grille for 1" Filter - Fixed Hinged - [Outer Dimensions: 27 5/8" X 14 5/8"] 18" Diameter Actual Filter Size – 19 Compatible With Duct 7in Applications This sheet metal DDAG-A-1212

Actual Filter Size – 19 3/4"w x 24 3/4" x 1"

+ Product Details Size – 12" X 4" is the size for the duct opening (floor/vent hole) measurement only

+ Product Details Size – 16"w X 10"h is the size for the duct opening measurement only

[Outer Dimensions: 14

But they are also the most visible representation of you air system

25" X 12" Steel Return Air Filter Grille for 1" Filter Fixed Hinged [Outer Dimensions: 27 5 8" X 14 5 8"] 18" Diameter Actual Filter Size – 19 Compatible With Duct 7in Applications This sheet metal DDAG A 1212 Actual Filter Size – 19 3 4"w x 24 3 4" x 1" + Product Details Size – 12" X 4" is the size for the duct opening (floor vent hole) measurement only