6" x 14" or 14" x 6" Cube Core Eggcrate Return Air Filter Grille for 1" Filter - Aluminum - White [Outer Dimensions: 8.5" X 16.5"] Brown + Product Details Perfect Fit Height_16in RG1612AL Product Details Size 14

+ Product Details Perfect Fit & Easy Sizing - Designed for a 10" x 14" or 14" x 10" duct opening (measured at the opening)

this thermostat guard is compatible with most standard thermostat models

+ Product Details Size – 28"w X 34"h is the size for the duct opening measurement only

actual front end outer dimensions are 3"

Actual Filter Size – 29 3/4"w x 23 3/4" x 1"

6" x 14" or 14" x 6" Cube Core Eggcrate Return Air Filter Grille for 1" Filter Aluminum White [Outer Dimensions: 8.5" X 16.5"] Brown + Product Details Perfect Fit Height_16in RG1612AL Product Details Size 14 + Product Details Perfect Fit & Easy Sizing Designed for a 10" x 14" or 14" x 10" duct opening (measured at the opening) this thermostat guard is compatible with most standard thermostat models