12x8 Duct Opening 1 Way Steel Air Supply Diffuser Register Vent Cover Grill for Sidewall and Ceiling The Listed size 14"x24" is

The Listed size 14"x24" is for inside duct opening measurement

If your duct opening size is 6'' x 6”

actual overall outside dimension is 18

actual outsize overall dimensions is 10“ wide by 8” high

The Listed size 6"x 6" is for inside duct opening measurement

12x8 Duct Opening 1 Way Steel Air Supply Diffuser Register Vent Cover Grill for Sidewall and Ceiling The Listed size 14"x24" isThe Listed size 12"x 8" is for inside duct opening measurement, outside dimension is 13. 75" X 9. 75" Stamped Face Steel Construction with 1 2" fin spacing for high air flow One Way Air Flow deflection Multi shutter damper with easy handle to adjust desired amount of air flow Individually packed