20"w X 20"h Extruded Aluminum Adjustable Surface 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"] w25h25 actual front end outer dimensions

actual front end outer dimensions are approximately 30 5/8" width X 22 5/8" height

ISO Supply Diffusers perform efficiently with air loadings of 6 to 30 air changes per hour (based on 10 ft

Design – Equipped with lever for full airflow control

High Quality – Easy unrestricted airflow for your HVAC system - 7/8" margin turnback

and we’ve help numerous contractors

20"w X 20"h Extruded Aluminum Adjustable Surface 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"] w25h25 actual front end outer dimensions+ 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