16" x 3" Aluminum Spiral Duct Air Vent Grille Cover - Fully Adjustable Double Deflection HVAC Air Supply [Outer Dimensions: 18w X 5"h] 6in diameter + Product Details Size –

+ Product Details Size – 12"w X 14"h is the size for the duct opening measurement only

High Quality – Rigid aluminum construction with counter-sunk screw holes (screws included) and no sharp edges

actual front end outer dimensions are approximately 14 5/8" width X 34 5/8" height

Actual Filter Size – 23 3/4"w x 31 3/4" x 1"

16" x 3" Aluminum Spiral Duct Air Vent Grille Cover - Fully Adjustable Double Deflection HVAC Air Supply [Outer Dimensions: 18w X 5"h] 6in diameter + Product Details Size –16"w X 3"h Is The Size For The Duct Opening Measurement Only, Actual Front End Outer Dimensions Are 18" Width X 5" Height SEE IN DESCRIPTION HOW TO MEASURE A GRILLE Installs Directly On Round & Oval Spiral Duct No Frames, Box or Other Attachments Needed Commercial Grade Aluminum Will Never Rust Designed for Warehouses, Factories, Workshops, Gymnasiums & Restaurants Easy Unrestricted Air Flow For Your HVAC System 180 Degrees Double Direction Adjustable