Shoemaker 151-18X18 18"x18" 4-Way Ceiling Diffuser - White 150 O - Steel Lever Operated Opposed Blade Damper 151 Series - Grille Only All Component Parts, Rivets, Linkage And Handle Enclosed In Valve To Assure Trouble-Free Operation Countersunk Mounting Holes For Flush Appearance, With Color Matching Phillips Posi-Drive Screws