6" x 6" [Duct Opening] Ceiling Supply Diffuser Vent Cover – 1-Way Airflow with Full Aluminum Frame, Back Blades & Opposing Blade Lever Damper [Outer Size: 9" x 9"] 4in diameter making it ideal for preventing

making it ideal for preventing tampering or unauthorized adjustments

+ Product Details Perfect Fit & Easy Sizing - Designed for a 10" x 8" or 8" x 10" duct opening (measured at the opening)

Actual Filter Size – 25 3/4"w x 23 3/4" x 1"

then you'll need a 14-inch round vent

6" x 6" [Duct Opening] Ceiling Supply Diffuser Vent Cover – 1-Way Airflow with Full Aluminum Frame, Back Blades & Opposing Blade Lever Damper [Outer Size: 9" x 9"] 4in diameter making it ideal for preventing+ Product Details Size Refers to duct opening only. The face frame extends roughly 1. 5" on each side. Do not measure the overall grille for sizing. Design All aluminum frame and back blades. Rustproof and built to last in moisture prone environments. Quiet Airflow Opposing blade damper design reduces vibration and noise for smoother air distribution. Clean Finish White powder coated surface resists chips, scratches, and discoloration over time. Easy