28" x 18" Cube Core Eggcrate Return Air Filter Grille for 1" Filter Color_Red Oak Wood + Product Details Size – 4 X 12 Is CRFG2028 Width_14in

+ Product Details Size – 14"w X 18"h is the size for the duct opening measurement only

actual front end outer dimensions are approximately 20 5/8" width X 22 5/8" height -

Optimized Comfort: By putting airflow control at your fingertips

+ Product Details Perfect Fit & Easy Sizing - Designed for a 26" x 16" OR 16" x 26" duct opening (measured at the opening)

Design – Removable frame for easy filter change & cleaning - uses a 1" thick filter

28" x 18" Cube Core Eggcrate Return Air Filter Grille for 1" Filter Color_Red Oak Wood + Product Details Size – 4 X 12 Is CRFG2028 Width_14in + Product Details Size – 14"w X 18"h is the size for the duct opening measurement only actual front end outer dimensions are approximately 20 5 8" width X 22 5 8" height