12" x 12" 3-WAY SUPPLY GRILLE - DUCT COVER & DIFUSER - LOW NOISE - For Ceiling - With Opposing Damper Blades [Outer Dimesnsions: 13.75" X 13.75"] Ceiling Grille Easy Unrestricted Air Flow For Youre HVAC System Carefully shrink wrapped with cardboard backing to prevent damage in shipment Screws Included No Sharp Surface Edges