12" x 16" or 16" x 12" Cube Core Eggcrate Return Air Filter Grille for 1" Filter - Aluminum - White [Outer Dimensions: 14.5" X 18.5"] w26h26 + Product Details Size - actual front end outer LS 1438 12BTP 15 Width_8in

+ Product Details Size - 20"w X 14"h is the size for the duct opening measurement only

Actual Filter Size – 13 3/4"w x 17 3/4" x 1"

Design – rigid gauge built for durability and long life in mind

actual front end outer dimensions are approximately 10 5/8" width X 16 5/8" height

With a solid base for stability

12" x 16" or 16" x 12" Cube Core Eggcrate Return Air Filter Grille for 1" Filter Aluminum White [Outer Dimensions: 14.5" X 18.5"] w26h26 + Product Details Size actual front end outer LS 1438 12BTP 15 Width_8in + Product Details Size 20"w X 14"h is the size for the duct opening measurement only Actual Filter Size – 13 3 4"w x 17 3 4" x 1"