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"] Material_Anodized Aluminum + Product Details Perfect Fit

+ Product Details Perfect Fit & Easy Sizing - Designed for a 30" x 6" OR 6" x 30" duct opening (measured at the opening)

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

+ Product Details Size - 12"w X 6"h X 2"d (for duct opening measurement only)

+ Product Details Size - 12"w X 6"h is the size for the duct opening measurement only

each available in a variety of high-quality materials like brushed nickel

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"] Material_Anodized Aluminum + Product Details Perfect Fit+ 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