4" X 20" Or 20" X 4" Heavy Duty Floor Grille - Fixed Blades Air Grille - Brown [Outer Dimensions: 5.75 X 21.75] Width_20in + Product Details Size – 4" Round Duct Pipe Product Details Size The SHEASC10W1-HP

+ Product Details Size – Duct end cap is 24" X 12" | 26-gauge galvanized steel end cap

actual front end outer dimensions are approximately 32 5/8" width X 16 5/8" height

Applications – The product is used for stopping all types of fittings and also used to terminate a rectangular duct run in an HVAC application with a rectangular duct cap

+ Product Details Size - 12"w X 36"h is the size for the duct opening measurement only

+ Product Details Size - 40"W X 4"H is (for duct opening measurement only)

4" X 20" Or 20" X 4" Heavy Duty Floor Grille Fixed Blades Air Grille Brown [Outer Dimensions: 5.75 X 21.75] Width_20in + Product Details Size – 4" Round Duct Pipe Product Details Size The SHEASC10W1 HP + Product Details Size – Duct end cap is 24" X 12" 26 gauge galvanized steel end cap actual front end outer dimensions are approximately 32 5 8" width X 16 5 8" height