Really good overall and the best co2 monitor I have seen. Listing positives and negatives - hopefully constructive for improvements later.

Positives
Notifications are great.
Still relatively works during travelling when still inside my bag; showing high co2 when on a train; showing high co2 before plane takeoff and then reducing and stabilising off once air filtration starts during the flight.
Smallest co2 monitor I have seen. Great for travellers.

Negative
The glass on the back is fragile and quickly broke after a small drop, but it still works. Probably plastic would have been better even if less visually nice.
The charging port feels like an Apple Magic Mouse situation where it’s on the bottom so it can’t be used whilst it’s charging. In this case it can still be used but you can’t stand it upright whilst it’s charging.

Feature requests
Customise ppm level of notifications rather than only 2000
Would love documentation on how to access the monitor with Bluetooth with code eg rust library would be great. want programmatic access to do things automatically!
Low battery notifications

I've been using AIRVALENT for a few months now, and I think it’s very accurate. I even bought one for my parents. They used to complain about bad sleep and feeling tired all the time, but now they monitor air in their bedroom and make sure to ventilate the room before bedtime, if AIRVALENT send them warning. They are very happy and feeling much more rested.

AIRVALENT's beautiful and modern design fits seamlessly into my home decor... I appreciate the attention to detail and craftsmanship that went into creating such a stylish yet functional product.

I've tried other air quality monitors before, but they didn’t survive my daughter and dogs attack.:D AIRVALENT has durable construction so I have high hopes for it. Customizable features make it the perfect addition to my home

AIRVALENT has been a game-changer for my allergies and asthma. Turns out it’s too humid in my home. Bought a dehumidifier and since using it and AIRVALENT, I've noticed a significant reduction in my symptoms. I can't recommend it enough!

I couldn't be happier with my AIRVALENT purchase. Not only is the
monitor compact and easy to use, but the customer service team went above and beyond to answer all my questions. Got the personalized option fo me and my coworkers.

AIRVALENT has truly transformed my home environment! I like its sleek
design and and accurate readings, I feel confident knowing I am breathing clean air,
especially when I do pilates and breathing excersises every evening.

Very happy and I recommend!

Recently we, at Bucher Municipal, made the decision to invest in AIRVALENT for our office, and we are quite satisfied. Not only did we get a customized sensor with our logo and design, but this device has truly transformed our workplace.
AIRVALENT monitors CO2 levels, temperature, and humidity, ensuring that we always follow the real-time situation.
What's truly remarkable is how practical and user-friendly the sensor is. Navigating AIRVALENT is a breeze - it combines functionality, style, and ease of use in one device. A truly worthwhile investment.

Mēģināju atrast mazāku, bet tiešām izskatās, ka šis ir mazākais co2 mērītājs. Šis man būs 4.veida aparāts, jo jau vairākus gadus sekoju aktualitātei. Lai izdodas paplašināt tirgu, prieks par jums!

Great CO2 sensor. Totally easy to use. Love the interchangeable screens. But now I'm hooked on checking the air quality! :)