28" X 20" Steel Return Air Filter Grille for 1" Filter - Removable Frame - [Outer Dimensions: 30 5/8" X 22 5/8"] 8in diameter 3 * insulation density is Compatible With Duct 7in Applications This sheet metal DDAG-A-1212

3 * insulation density is 30kgs/cbm = 0

+ Product Details Size – 28"w X 18"h is the size for the duct opening measurement only

+ Product Details Size – 26"w X 30"h is the size for the duct opening measurement only

+ Product Details Size - 8"w X 30"h is the size for the duct opening measurement only

actual front end outer dimensions are approximately 12 5/8" width X 26 5/8" height

28" X 20" Steel Return Air Filter Grille for 1" Filter Removable Frame [Outer Dimensions: 30 5 8" X 22 5 8"] 8in diameter 3 * insulation density is Compatible With Duct 7in Applications This sheet metal DDAG A 1212 3 * insulation density is 30kgs cbm = 0 + Product Details Size – 28"w X 18"h is the size for the duct opening measurement only