1.9in1 multifunctional air quality monitor: An upgraded indoor air quality monitor capable of accurately assessing multiple air quality metrics, including formaldehyde (HCHO), PM2.5, PM1.0, PM10, TVOC concentrations, as well as temperature, humidity, AQI, and scheduled timing. It is crucial to be aware of the air quality in your living space. 2.Portable air detector: Monitor indoor air quality anywhere. This compact air quality detector is ideal for use at home, in the kitchen, bedroom, office, school, car, hotel, or during travel and camping—especially in spaces occupied by babies, children, and pregnant women. 3.Easy to use: Simply press the function button to operate this air monitor. The updated user manual is straightforward and easy to follow. The smart air tester can monitor environmental changes over a period that matters to you. Carry it anywhere to check air quality. Additionally, you can set a default formaldehyde threshold; if levels exceed this value, an alert will be triggered. 4.Test technology: Semiconductor sensor.