20" X 18" 2-Way Air Supply Grille – Steel HVAC Vent Cover with Damper, Wall/Ceiling Register, White Compatible With Duct 6in Ideal for Walls & Ceilings:

Ideal for Walls & Ceilings: Designed for seamless installation in standard 30" X 6" duct openings

actual front end outer dimensions are approximately 38 5/8" width X 26 5/8" height -

Actual Filter Size – 33 3/4"w x 21 3/4" x 1"

+ Product Details Size – 18"w X 34"h is the size for the duct opening measurement only

+ Product Details Size - 26"w X 6"h is the size for the duct opening measurement only

20" X 18" 2-Way Air Supply Grille – Steel HVAC Vent Cover with Damper, Wall/Ceiling Register, White Compatible With Duct 6in Ideal for Walls & Ceilings:+ Product Details Outer dimensions: 21. 75"W x 19. 75"H fits a 20" X 18" duct opening Durable stamped steel construction ensures long lasting performance Designed for sidewall and ceiling installation with included screws Multi shutter damper with easy lever for precise airflow control Smooth powder coated white finish for a sleek look and scratch resistance + Product Description Maximize your homes airflow with this premium Air Supply Grille air