Review on 🌡️ ECOWITT Temperature Humidity Particle Detection: Advanced Monitoring Technology for Optimal Indoor Environments by Patrick Arnautov

Arrived quickly with no shipping issues from Revain. Works great with Ecowitt HP3501 *after firmware update* (1.6.2 or higher; current version at the time of writing this article is 1.6.9) - this is NOT the same firmware update you can do with the app; You need an SD card for this. Otherwise it just won't show up. Check your device's About page to ensure you have the correct firmware installed. It's always nice to see more data on the Ecowitt weather panel. Unlike the WH41/WH42 sensors, this one displays PM2.5 and PM10 separately. The CO2 readings are close to other sensors I've used (Airthings and Withings scale) so I've had faith in them so far.