16" x 3" Aluminum Spiral Duct Air Vent Grille Cover - Fully Adjustable Double Deflection HVAC Air Supply [Outer Dimensions: 18w X 5"h] Compatible With Duct 8in Actual Filter Size – 31

Actual Filter Size – 31 3/4"w x 21 3/4" x 1"

Actual Filter Size – 17 3/4"w x 7 3/4" x 1"

Actual Filter Size – 9 3/4"w x 31 3/4" x 1"

actual front end outer dimensions are approximately 11

Sleek Design – The clear and unobtrusive design ensures it blends seamlessly with any home

16" x 3" Aluminum Spiral Duct Air Vent Grille Cover - Fully Adjustable Double Deflection HVAC Air Supply [Outer Dimensions: 18w X 5"h] Compatible With Duct 8in Actual Filter Size – 3116"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