Great device to measure air quality levels. Inexpensive and could create a fun project. I have 3 sometimes 4 monitoring the air quality around the house. A great way to re-purpose an old computer to be an air quality monitor station.
It worked out of the box. Ohmtech.io is completely responsive to customers, always there for support. They shipped the product ASAP! The documentation was very complete and easy to understand, even if it's a bit like reading shampoo instructions as you just plug in and point to /dev/ttyACMnn in Linux (Fedora 30 and with my Raspberry Pi). Readings and sensors seem to be very accurate according to my readings, specially the Bosch IAQ. Completely recommend.
This is a professional quality device, and was delivered quite quickly. It works very well, precisely as described in the (quite detailed and well written) documentation online. The firmware is stable, simple to interact with and functional. Overall, this is an excellent device to use, if the use case (USB attached indoor environment sensor) fits your requirements! If in doubt, have a look at the pdf documentation, it describes the functionality quite thoroughly.