16" X 8" ADJUSTABLE AIR SUPPLY DIFFUSER - HVAC Vent Duct Cover Sidewall or Ceiling 18in diameter actual front end outer dimensions 4 X 12 Is CRFG2028 Width_14in

actual front end outer dimensions are 25" Width X 13" Height

Think of the diameter as a straight line from one end to the other

actual front end outer dimensions are 11

+ Product Details Size - 24"w X 30"h is the size for the duct opening measurement only

Tamper-Proof Design – Provides robust protection to prevent unauthorized access and ensure consistent thermostat settings

16" X 8" ADJUSTABLE AIR SUPPLY DIFFUSER HVAC Vent Duct Cover Sidewall or Ceiling 18in diameter actual front end outer dimensions 4 X 12 Is CRFG2028 Width_14in actual front end outer dimensions are 25" Width X 13" Height Think of the diameter as a straight line from one end to the other