This HomeKit compatible small wireless sensor measures temperature, humidity, and air pressure.
A CR2032 battery powers it; on paper, the battery life is about two years.
Pairing is straightforward. Hold the reset button at the top of the sensor for 5s to get it into pairing mode, and add it the usual way on the Aqara app.
All three types of readings will be shown on the Aqara app. However, because Apple HomeKit doesn’t support air pressure readings, only the temperature and humidity will show up in the Apple Home app.