10"x 8" 2-Way Stamped Face Steel Ceiling/sidewall Air Supply Register The listed size 12" x

The listed size 12" x 8" is for the inside duct opening measurement

75” wide by 7

NSF/ANSI 62

and other gas appliances

10"x 8" 2-Way Stamped Face Steel Ceiling/sidewall Air Supply Register The listed size 12" xFirst thing to know about size selection: take the vent cover off the wall or ceiling. Measure the duct opening where the vent can fit in. Use the measurement to determine right size to buy. This product has listed size 10w X 8h is for duct opening measurement only, actual outsize overall dimensions is 11. 75 wide by 9. 75 high. If your duct opening size is 10 x 8, this is the right size and will fit in well. If you measure outside or surface size,