Adjustable Side Wall/Ceiling Registers

Adjustable air registers allows all horizontal directions of air flow.  Each blade is independently adjustable to desired direction horizontally. The size shown is for the inside measurement, i.e. the duct opening size.  For example, if you take off the old register and measured size of the duct hole is 10" x 4", then order 10" x 4".  Measuring outside/surface size in this case will mislead you to order 12" x 6", too big to fit in the 10" x 4" duct size.