12" X 12" Steel Access Panel Removable Door For Wall / Ceiling Application (Lock and Key) With Frame - [Outer Dimensions: 13" Width X 13" Height] 12" Diameter + Product Details Perfect Fit Compatible With Duct 7in Applications This sheet metal DDAG-A-1212

+ Product Details Perfect Fit & Easy Sizing - Designed for a 26" x 20" OR 20" x 26" duct opening (measured at the opening)

+ Product Details Size - 22"w X 34"h is the size for the duct opening measurement only

Complies with industry standards of USA: ASTM D-882

+ Product Details Size - 12"w X 32"h is the size for the duct opening measurement only

Actual Filter Size – 21 3/4"w x 13 3/4" x 1"

12" X 12" Steel Access Panel Removable Door For Wall Ceiling Application (Lock and Key) With Frame [Outer Dimensions: 13" Width X 13" Height] 12" Diameter + Product Details Perfect Fit Compatible With Duct 7in Applications This sheet metal DDAG A 1212 + Product Details Perfect Fit & Easy Sizing Designed for a 26" x 20" OR 20" x 26" duct opening (measured at the opening) + Product Details Size 22"w X 34"h is the size for the duct opening measurement only