20"w X 6"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 21.75"w x 7.75"h] w6h6 + Product Details Size –

+ Product Details Size – 24" x 24" with 8" collar T-Bar drop ceiling perforated return grill - metal back casing

actual front end outer dimensions are approximately 24 5/8" width X 27 5/8" height

Actual Front End Outer Dimensions Are 16" Width X 5" Height - SEE IN DESCRIPTION HOW TO MEASURE A GRILLE

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

20"w X 6"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 21.75"w x 7.75"h] w6h6 + Product Details Size –+ Product Details Size 20"w X 6"h X 2"d (for duct opening measurement only); actual front end outer dimensions are 21. 75" Width X 7. 75" Height Weather and Pest Proof These louvers are especially designed to prevent water from entering your home, and with a built in back 1 2" mesh they also protect you from annoying rodents like mice, rats, birds, and squirrels High Quality Aluminum The premium durable aluminum will never rust and it will never wear