10"x 4" (Duct Opening Size) 3-Way Stamped Face Steel Ceiling/sidewall Air Supply Register - Vent Cover - Actual Outside Dimension 11.75" X 5.75" This product has listed size

This product has listed size 10“w X 8”h is for duct opening measurement only

Stamped face steel construction with 1/2" fin spacing for high air flow

If your duct opening size is 10'' X 10''

The outside or overall size is 2

10"x 4" (Duct Opening Size) 3-Way Stamped Face Steel Ceiling/sidewall Air Supply Register - Vent Cover - Actual Outside Dimension 11.75" X 5.75" This product has listed sizeThe Listed size 10"x 4" is for inside duct opening measurement, actual outside dimension is 11. 75" X 5. 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