Ceiling Grille - 3 Cone Step Down Diffuser - 12" x 12" - 8" Collar w18h18 actual front end outer dimensions

actual front end outer dimensions are approximately 34 5/8" width X 24 5/8" height

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

with an additional 1 7/8" width and 2" height

High Quality – Solid stamped steel with counter-sunk screw holes (screws included) and no sharp edges

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

Ceiling Grille - 3 Cone Step Down Diffuser - 12" x 12" - 8" Collar w18h18 actual front end outer dimensions+ 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