... LCD backlitindicating optimal/moderate/poor ventilation u Two alarm ways: buzzer alarm and backlight colours switch u Provide optional 1xrelay ... toluene,formaldehyde and cigarette smoke, alcohol, H2S, and carbon monoxide. So it is very suitable to monitor the general ... Description Power Supply G01-CO2-B520C CO2, TVOC, temperature and humidity monitor/alarm Three-color backlit LCD, buzzer alarm 24VAC/ ...