20"w X 20"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: 21.125" X 21.125"] Compatible with Duct 8" + Product Details Size –

+ Product Details Size – 6" round duct opening-

+ Product Details Size - 6"w X 26"h is the size for the duct opening measurement only

Crafted from high-quality powder-coated steel

actual front end outer dimensions are approximately 34 5/8" width X 28 5/8" height

Actual Filter Size – 23 3/4"w x 9 3/4" x 1"

20"w X 20"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: 21.125" X 21.125"] Compatible with Duct 8" + Product Details Size –+ Product Details Size 20"w X 20"h Is The Size For The Duct Opening Only, Dimensions With Outer End are 21. 125" X 21. 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