18" x 8" Cube Core Eggcrate Return Air Filter Grille for 1" Filter 14" Diameter + Product Details Size - 14" Round Duct Pipe For 10 duct opening FR M 414 White

+ Product Details Size - 26"w X 10"h is the size for the duct opening measurement only

+ Product Details Size – 12" X 2" is the size for the duct opening (floor/vent hole) measurement only

+ Product Details Perfect Fit & Easy Sizing - Designed for a 34" x 20" Or 20" x 34" duct opening (measured at the opening)

Actual Filter Size – 19 3/4"w x 15 3/4" x 1"

18" x 8" Cube Core Eggcrate Return Air Filter Grille for 1" Filter 14" Diameter + Product Details Size 14" Round Duct Pipe For 10 duct opening FR M 414 White + Product Details Size 26"w X 10"h is the size for the duct opening measurement only + Product Details Size – 12" X 2" is the size for the duct opening (floor vent hole) measurement only