Great product: well made, looks good, well designed interface

I’ve been using the monitor to determine if my cooktop's front gas burners spew more CO2 into the kitchen than the rear burners (oh yes they do). More significantly, I used the monitor in our 11 person office to determine that, even with the HVAC system running continuously, ostensibly with 30% fresh air mixed in, the CO2 level more then doubled during the workday from the low 400s up to the 900s and higher. Workmates were suitably horrified!