8" BUTTERFLY DAMPER - Control Your Airflow on drop ceiling grilles of 24x24 (8" round duct opening) 8" Diameter + Product Details Size –

+ Product Details Size – 12" x 24" or 24" x 12" is the size for the duct opening measurement only

actual front end outer dimensions are approximately 22 5/8" width X 34 5/8" height -

+ Product Details Size - 18"w X 4"h is the size for the duct opening measurement only

+ Product Description Enhance your HVAC system with our Aluminum Return Filter Linear Bar Grille

8" BUTTERFLY DAMPER - Control Your Airflow on drop ceiling grilles of 24x24 (8" round duct opening) 8" Diameter + Product Details Size –Control Your Airflow on drop ceiling grilles See our separate listing for T Bar supply grille Check Out This Asin For Matching T Bar Drop Ceiling Grille: B007CNEJZK These are airflow control components made to connect to supply grilles of the drop ceiling, the T Bar vent covers. See our separate listing of T Bar Supply Grilles. Metal Fab A brand you can trust. Some of our best features aren't readily apparent, but youll appreciate the benefits over a