Another great tool in the toolkit for preventing COVID exposure. Although it cannot measure COVID in the air, CO2 is a good measure of airflow, with high CO2 corresponding to poor airflow and greater chance of catching COVID if someone in the room is positive. Unlike cheaper options the Aranet4 is very accurate and comes with a bluetooth connection for viewing the history. I like to keep it in a little pouch of my belt when out and about.

This little piece of technology really opened my eyes to the how bad the CO2 concentration could get in my home office. It was reaching well over 2000ppm at times, no wonder we've had a hard time focusing on work!

We open the windows a lot more now that we have a proper measure the ventilation. It's one thing to know you should be opening your windows, it's another to actually measure the impact!

The setup couldn't be easier, pop the included batteries in, close the compartment and you're set for the next 4 years.
The iOS app is easy to use and pair to the unit as well, and it's very helpful to be able see the evolution of the CO2 levels over time and how what you do affects it.

I considered buying a CO2 monitor off aliexpress for much cheaper instead, but Aranet4 being the gold standard makes me a lot more confident in the accuracy of the measurements, and the battery life and the added graph data made it worth it for me.

Well worth the money. You do *not* need to change any of the settings, just plug the batteries in and go. Well worth the money, the associated apps are well designed and useful too.

Deliberated long and hard about buying a cheap CO2 monitor from China but haven't regretted buying a proper piece of equipment. Quality build, excellent performance, love the e-reader type screen plus how I can customise it and the ability to view graphs and past data on my phone. It's been very helpful for checking air quality at home and other indoor venues. Outstanding service, it shipped the day I ordered it and arrived the next morning.

Worth the $$$. Long battery life, accurate readings

Excellent monitor - wouldn't choose any other brand. Operates exactly as expected.