No need for additional shutters.

Shutter maintains good ventilation.

Even if electric power is off, the blades close automatically with no need for manual control.

Simple to operate: When turned on, the shutter opens to become the blades of the fan. When off,    they automatically form a closed shutter.

It is easy to connect the unit to thermostats, gas detectors, etc.

The blades close completely, forming a shield against insects and unwelcome odors.

Living room, bathroom, office, restarant, office, library, smoking room, workshops,etc.