Ceiling Grille - 3 Cone Step Down Diffuser - 12" x 12" - 8" Collar w18h18 Actual Filter Size – 23

Actual Filter Size – 23 3/4"w x 31 3/4" x 1"

+ Product Details Size - 24"w X 6"h is the size for the duct opening measurement only

thanks to counter-sunk screw holes and included screws

The crank handle lever makes it easy to adjust to every weather situation

while the ingenious dial-controlled damper empowers you to effortlessly regulate airflow using your foot

Ceiling Grille - 3 Cone Step Down Diffuser - 12" x 12" - 8" Collar w18h18 Actual Filter Size – 23+ Product Details Size 12"w X 12"h. These are specially sized to fit into all drop ceilings, 24"x 24", also called T Bar systems. Can be hooked up with our "Butterfly Dampers" for precise airflow control. For 8" Round Duct Opening Spiral or Flex Powder Coat Finish Smooth, shiny, scratch resistant, beautiful. Looks like it was just waxed Heavy Gauge Steel Heavier gauge than needed, built for durability and long life in mind, but still very thin