The Essentials CO2 Monitor is a user-friendly indoor air quality monitor, which detects CO2 levels using a Non-Dispersive Infrared (NDIR) spectroscopic sensor. Its large-format display shows the real-time CO2 level, ambient temperature and relative humidity, along with a clock and a bar-chart indicating how CO2 levels have changed over the previous 24 hours. It can be set to give a green / amber / red backlight to indicate normal / raised / high levels of CO2, and there is also a programmable audible alarm which will sound when the CO2 level reaches a user-set threshold. 

The backlight can be switched off or set to automatically dim from 10pm to 6am. If preferred, the backlight colour can be selected from seven colour options.

Powered via a USB lead from a mains power adaptor (supplied) or from a PC or USB Power Bank.