... Provide three relays output Control. SAS908VOC Indoor Air Qulity Monitor/Alarm Features:1. Real time monitor ambiance air quality2. Gas ... Monitor temperature and relative humidity4. Preset warning point of buzzer alarm and backlight5. Provide three relays output to control a ventilator6 ... , sitting room, study and dinner room, kindergarten, classroom, office, car, restaurant, and other public places.