6"W X 4"H [Duct Opening] ALUMINUM RETURN GRILLE - Easy Air Flow - Linear Bar Grilles [Outer Dimensions: 7.875"W X 5.875"H] 18" Round Duct Pipe installation is a breeze

installation is a breeze

Its locking eight-tumbler mechanism and supplied key safeguard your thermostat from tampering

+ Product Details Perfect Fit & Easy Sizing - Designed for a 22" x 18" OR 18" x 22" duct opening (measured at the opening)

+ Product Details Size - 16"w X 20"h X 2"d (for duct opening measurement only)

6"W X 4"H [Duct Opening] ALUMINUM RETURN GRILLE - Easy Air Flow - Linear Bar Grilles [Outer Dimensions: 7.875"W X 5.875"H] 18" Round Duct Pipe installation is a breeze+ Product Details Size 6"w X 4"h is the size for the duct opening measurement only, actual front end outer dimensions are approximately 7. 875" width X 5. 875" height. High Quality High quality aluminum with counter sunk screw holes (screws included) and no sharp edges. Design Unrestricted airflow For Your HVAC system noise free components no vibrating louvers etc. Powder Coat Finish Smooth, shiny, scratch resistant, beautiful. Looks like it was just