6" x 18" or 18" x 6" Cube Core Eggcrate Return Air Filter Grille for 1" Filter - Aluminum - White [Outer Dimensions: 8.5" X 20.5"] Color_Red Oak Center Core is Removable for 14" Round Duct Pipe FR M 414 White For 10 duct opening

Center Core is Removable for Easy Access and Maintence

+ Product Details Perfect Fit & Easy Sizing - Designed for a 32" x 32" duct opening (measured at the opening)

this model ensures top-notch air quality

+ Product Details Size – 12" x 20" or 20" x 12" is the size for the duct opening measurement only

Experience uniform air distribution in every corner

6" x 18" or 18" x 6" Cube Core Eggcrate Return Air Filter Grille for 1" Filter Aluminum White [Outer Dimensions: 8.5" X 20.5"] Color_Red Oak Center Core is Removable for 14" Round Duct Pipe FR M 414 White For 10 duct opening Center Core is Removable for Easy Access and Maintence + Product Details Perfect Fit & Easy Sizing Designed for a 32" x 32" duct opening (measured at the opening)