Abilities
*usable in return and offloading for all places.
*  Instal location on the wall or false wall
*usable in ventilation control in a zoon
* very low in pressure for blowing and offloading air (ventilation)
 *Able to instal kinds of dampers for ventilation control
*Able toventilate in 1   2   3   4   - side and rotating
* Long length  throwing
* ventilation in manner of string  
* Low voice
 
Use cases
*Usable in return and offloading for all places.
*  Instal location on the wall or false wall
 *usable in ventilation control in a zoon
* very low in pressure for blowing and offloading air (ventilation)