12"W X 10"H [Duct Opening] Aluminum Double Deflection Adjustable Air Supply HVAC Diffuser - [Outer Dimensions: 13.6"W X 11.6"H] fixed bar Actual Filter Size – 9

Actual Filter Size – 9 3/4"w x 17 3/4" x 1"

+ Product Details Size - 28"w X 20"h is the size for the duct opening measurement only

Actual Filter Size – 33 3/4"w x 9 3/4" x 1"

listed size +2"

actual front end outer dimensions are approximately 20 5/8" width X 22 5/8" height -

12"W X 10"H [Duct Opening] Aluminum Double Deflection Adjustable Air Supply HVAC Diffuser - [Outer Dimensions: 13.6"W X 11.6"H] fixed bar Actual Filter Size – 9+ 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,