12" x 6" Adjustable Blade Sidewall Ceiling Register Vent Cover Diffuser Heavy Duty Stamped Steel (Listed Size is for Duct Opening or Inside Measurement, Outside Surface 13.8" x 8"))

Adjustable Air Register – Diffuser for sidewall or ceiling applications. The listed size 12“ X 6” is for duct opening measurement only, Actual outsize overall dimensions is 13.8“ wide by 8” high. Size Selection Guide: 1. Measure the size of the air duct opening(the size of the “hole” ). 2. Select the listed size that match the duct opening size. 3. The outside or overall size is 2” larger for both width and length so it can cover the “hole”. 4. Do not use outside measurement for size selection.