12" x 12" - 2-Way Extruded Aluminum Ceiling Diffuser Square - HVAC Vent Cover Color_R-4.2 Yellow + Product Details Size – Compatible With Duct 7in Applications This sheet metal DDAG-A-1212

+ Product Details Size – 16" x 36" or 36" x 16" is the size for the duct opening measurement only

+ Product Details Size - 26"w X 20"h is the size for the duct opening measurement only

Actual Filter Size – 7 3/4"w x 9 3/4" x 1"

+ Product Details Size - 30"w X 12"h X 2"d (for duct opening measurement only)

actual front end outer dimensions are approximately 20 5/8" width X 10 5/8" height

12" x 12" 2 Way Extruded Aluminum Ceiling Diffuser Square HVAC Vent Cover Color_R 4.2 Yellow + Product Details Size – Compatible With Duct 7in Applications This sheet metal DDAG A 1212 + Product Details Size – 16" x 36" or 36" x 16" is the size for the duct opening measurement only + Product Details Size 26"w X 20"h is the size for the duct opening measurement only