[Multi-Function Indoor Air Monitor] It is an advanced multi-functional quality monitor indoor equipped with a variety of high quality sensing chips & integrated fan. Real-time monitoring of a range of pollutant indicators such as CO2, TVOC, PM2.5, PM1.0,HCHO, temperature, humidity and time of day. The air quality detector combines essential-healthy air indicator functions. It can assist in effective monitoring of indoor air quality, which is an essential and good helper for home. [CO2 Alarm Function] The CO2 alarm beeps immediately when it detects a CO2 concentration above 1000 ppm (outside the expected range). The purpose of the CO2 alarm is to alert you immediately so that you can take immediate action to improve CO2 concentration, such as opening a window or door, or stopping the activity that is causing the elevated reading. [Easy to Use] Each turn on, CO2 detector need to automatic calibration, so please put the air quality detector in a ventilated place, after 1-2 minutes calibrating, CO2 tester can be used normally. [Wide Range Of Applications] This indoor air quality meters is suitable for air quality testing in diverse settings such as homes, offices, schools, hospitals, and vehicles. Stylish modern design, it can also as an attractive home decoration, whether placed in a living room or on an office desk, enhances the aesthetic appeal of the space while providing convenient daily clocks functions to facilitate everyday routines. Note:Dear customer, compare with other CO2 meters, please allow the differece (about ±50 ppm). Please note:the physical slightly color difference or difference, does not affect the use, please do not mind, thank you! Colour:As Shown Material:ABS Package Contents: 1 * Air Quality Monitor 1 * English instruction manual Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.