OV-R is a wall transfer unit that provides effective air transfer in a variety of installations. It has been designed to provide air transfer between neighbouring residential, hotel and office rooms over other settings. Its design facilitates low air transfer resistance. It has a slim and compact design for inconspicuous deployment. The OV-R wall air transfer device consists of two covers from galvanised sheet steel with a powder coating.

The OV-R features acoustic attenuation foam that is attached to the inner sides of the covers. Acoustic attenuation foam lining mat AL-OV-R for the wall opening is a part of the OV-R package. This provides highly effective sound attenuation. The OV-R has a low generated sound level when operating. Other sizes are available in this range.