16"w X 20"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 17.75"w x 21.75"h] 6" Diameter + Product Details Size -

+ Product Details Size - 8" Diameter is the size for the duct opening measurement only

actual front end outer dimensions are 11

12" x 8" Decorative Wood Air Vent HVAC Duct Cover Grille - Polished Finish Red Oak Wood - 2-Way Air Direction

Actual Filter Size – 25 3/4"w x 19 3/4" x 1"

+ Product Description Protect and secure your thermostat with this high-quality Clear Plastic Thermostat Guard

16"w X 20"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 17.75"w x 21.75"h] 6" Diameter + Product Details Size -+ Product Details Size 16"w X 20"h X 2"d (for duct opening measurement only); actual front end outer dimensions are 17. 75" Width X 21. 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