RV and Home White Stamped Steel Floor Diffuser/Register with Damper 12" X 2" (Duct Opening Size) Outside Dimension 13.5"x 3.75" Distance between the centers of

Distance between the centers of two screws is 13"

actual outsize overall dimensions is 13

durable material to withstand many different operating conditions

If your duct opening size is 12” x 6”

RV and Home White Stamped Steel Floor Diffuser/Register with Damper 12" X 2" (Duct Opening Size) Outside Dimension 13.5"x 3.75" Distance between the centers ofThe Listed size 12"x 2" is for inside duct opening measurement, actual outside dimension is 13. 5"x 3. 75" Butterfly damper with easy foot operated control dial for desired air flow Two sunk screw holes located at both sides of the register for ceiling and wall mounting with included screws. Distance between the two screw holes is 13. 25". White powder coating with matte finish Individually shrink wrapped with card board pad in the back for extra