Ceiling Grille - 3 Cone Step Down Diffuser - 12" x 12" - 8" Collar Compatible with Duct 8" making it a reliable choice

making it a reliable choice for improving indoor air quality

+ Product Details Size - 18"w X 14"h is the size for the duct opening measurement only

Actual Filter Size – 19 3/4"w x 9 3/4" x 1"

the gap will expand and retract to meet perfect air supply needed

40"w X 16"h Is The Size For The Duct Opening Measurement Only

Ceiling Grille - 3 Cone Step Down Diffuser - 12" x 12" - 8" Collar Compatible with Duct 8" making it a reliable choice+ 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