12" x 34" or 34" x 12" Cube Core Eggcrate Return Air Grille Insulated Line Set + Product Description Our Clear

+ Product Description Our Clear Plastic Thermostat Guard is the ultimate solution for protecting your thermostat while ensuring universal compatibility

+ Product Details Perfect Fit & Easy Sizing - Designed for a 10" x 20" duct opening (measured at the opening)

+ Product Details Size - 30"w X 18"h is the size for the duct opening measurement only

Actual Filter Size – 27 3/4"w x 29 3/4" x 1"

12" x 34" or 34" x 12" Cube Core Eggcrate Return Air Grille Insulated Line Set + Product Description Our Clear+ Product Details Size 12" x 34" or 34" x 12" is the size for the duct opening measurement only, actual front end outer dimensions are approximately 13. 75" X 35. 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