4" Circular Round Plastic HVAC Supply Grille Air Diffuser -Vent Duct Cover [Outer Dimensions: 6"] w34h34 + Product Details Size -

+ Product Details Size - 18"w X 14"h is the size for the duct opening measurement only

+ Product Details Size – 16"w X 16"h is the size for the duct opening measurement only

Design – Easy unrestricted airflow for your HVAC system - 50° angled to provide maximum airflow

This versatile diffuser is adaptable to various airflow needs

Whilst the maximum pressure for R410 is 700 PSI

4" Circular Round Plastic HVAC Supply Grille Air Diffuser -Vent Duct Cover [Outer Dimensions: 6"] w34h34 + Product Details Size -+ Product Details Size 4" Diameter is the size for the duct opening measurement only, actual front end outer dimensions are 6" diameter. Design Made of strong durable ABS plastic, will last forever & never rust. Easy removal for cleaning. Airflow Improved airflow dynamics long neck bBody reduced noise design integrated spring fasteners. Easy Installation Just pop the diffuser right into the wall duct hole and the side springs will hold it right into