Siemens S55720-S458 QSA2700D FINE DUST SENSOR +DISPLAYSiemens S55720 S458 QSA2700D Fine dust sensor +displayThe Room Condition Monitor is designed for indoor use only to monitor critical environments by providing differential pressure indication and additional parameters such as temperature, relative humidity, air changes per hour, and user defined information. Typically, this is between a monitored room and a reference space such as a corridor or ante room. The unit also provides monitoring, audio and