Rectangular Duct End Cap | 20" X 12" End Cap 12" Diameter + Product Details Size -

+ Product Details Size - 24"w X 36"h is the size for the duct opening measurement only

Actual Filter Size – 31 3/4"w x 31 3/4" x 1"

and smooth surface for years to come

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Rectangular Duct End Cap | 20" X 12" End Cap 12" Diameter + Product Details Size -+ Product Details Size Duct end cap is 20" X 12" 26 gauge galvanized steel end cap, rectangular shape. Premium Quality Our rectangular duct cap is made of high quality galvanized sheet metal material (galvanized steel construction for durability and rust prevention). Made in the USA. 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.