12"W X 10"H [Duct Opening] Aluminum Double Deflection Adjustable Air Supply HVAC Diffuser - [Outer Dimensions: 13.6"W X 11.6"H] Compatible with Duct 10" + Product Details Size -

+ Product Details Size - The listed 8" diameter refers specifically to the size of the duct opening

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

Elevate your living space with this sophisticated addition

4" X 12" Is The Size For The Duct Opening (floor/vent hole) Measurement Only

Actual Filter Size – 7 3/4"w x 27 3/4" x 1"

12"W X 10"H [Duct Opening] Aluminum Double Deflection Adjustable Air Supply HVAC Diffuser - [Outer Dimensions: 13.6"W X 11.6"H] Compatible with Duct 10" + Product Details Size -+ Product Details Size 12"w X 10"h is the size for the duct opening measurement only, actual front end outer dimensions are approximately 13. 6" width X 11. 6" height. Design Full Control Vertical Horizontal Air flow Direction. Horizontal blades in the front, Vertical blades in the back, both individually adjustable. High Quality Aluminum The premium durable aluminum will never rust and it will never wear through leaving the material with an elegant,