12" x 26" or 26" x 12" Cube Core Eggcrate Return Air Grille Compatible with Duct 6" this thermostat guard is compatible

this thermostat guard is compatible with most standard thermostat models

Actual Filter Size – 33 3/4"w x 5 3/4" x 1"

Actual Filter Size – 25 3/4"w x 5 3/4" x 1"

To Maximize Ventilation Results

75" width X 25

12" x 26" or 26" x 12" Cube Core Eggcrate Return Air Grille Compatible with Duct 6" this thermostat guard is compatible+ Product Details Size 12" x 26" or 26" x 12" is the size for the duct opening measurement only, actual front end outer dimensions are approximately 13. 75" X 27. 75". High Quality High quality, rust free aluminum construction with smooth finished edges and counter sunk screw holes (screws included); no sharp edges.. Installation Location sidewall and ceiling. Design Cubic core eggcrate design Offers highest airflow efficiency at almost 95%, reducing