10"x 6" (Duct Opening Size) 3-Way Stamped Face Steel Ceiling/sidewall Air Supply Register - Vent Cover - Actual Outside Dimension 11.75" X 7.75" Distance between the centers of

Distance between the centers of two screws is 11"

this register allows for optimal airflow distribution from your HVAC system

18" long heavy duty steel construction with oil brushed powder coating finish

The Listed size 16"x16" is for inside duct opening measurement

10"x 6" (Duct Opening Size) 3-Way Stamped Face Steel Ceiling/sidewall Air Supply Register - Vent Cover - Actual Outside Dimension 11.75" X 7.75" Distance between the centers ofThe Listed size 10"x 6" is for inside duct opening measurement, actual outside dimension is 11. 75" X 7. 75" Stamped Face Steel Construction with 1 2" fin spacing for high air flow Three Way Air Flow deflection Design Multi shutter damper with easy handle to adjust desired amount of air flow Individually shrink wrapped with card board pad in the back for extra protection