16"w X 16"h Extruded Aluminum Adjustable Core Mount Supply Ceiling HVAC Air Grille – Interchangeable: 1-Way, 2-Way, 3-Way or 4-Way - Vent Duct Cover [Outer Dimensions: 17.125" X 17.125"] Color_Red Oak Universal Fit – Measures 3-7/8"

Universal Fit – Measures 3-7/8" wide x 3-1/2" high x 3" deep

+ Product Details Size - 34"w X 4"h is the size for the duct opening measurement only

Actual Filter Size – 19 3/4"w x 21 3/4" x 1"

each diffuser is carefully shrink-wrapped with a sturdy cardboard backing

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

16"w X 16"h Extruded Aluminum Adjustable Core Mount Supply Ceiling HVAC Air Grille – Interchangeable: 1-Way, 2-Way, 3-Way or 4-Way - Vent Duct Cover [Outer Dimensions: 17.125" X 17.125"] Color_Red Oak Universal Fit – Measures 3-7/8"+ Product Details Size 16"w X 16"h Is The Size For The Duct Opening Only, Dimensions With Outer End are 17. 125" X 17. 125". Design Re configurable Interchangeable Sections Easily convertible into 1 Way, 2 Way, 3 Way, or 4 Way Just lift sections and rotate to re configure direction. High Quality Aluminum The premium durable aluminum will never rust and it will never wear through leaving the material with an elegant, beautiful, and smooth surface, adds