Features: 3 in 1 function, real-time detection and monitoring, comprehensive understanding of indoor carbon dioxide, humidity and temperature three indicators, detection of air quality, and for protection of respiratory for health. When the monitoring environment carbon dioxide exceeds the standard, the reading of the carbon dioxide detector will increase, the indicator light will be red, and an alarm will sound. Built-in automatic calibration algorithm, high sensitivity, low power consumption. One-button operation, simple and easy to use, separate button design, it can be started and used with one click, intuitively display CO2, temperature, humidity values, avoid complex operations, fast and convenient, clear readings at a glance. Small and portable, easy to carry, does not take up too much space, can be placed on the desktop at will. Specifications: Material: ABS Size: 90x80x40mm/ 3.54x3.15x1.57 in Test range: 400~5000PPM Accuracy tolerance: CO2 concentration: (50ppm+5%reading) Unit of measurement: PPM/°C/%RH Temperature: 0.3°C Humidity: 2%RH Power supply mode: USB/lithium battery Response time: less than 120S Value update time: less than 3S Package Includes: 1X Air Quality Monitor note: Please allow 1-3cm error due to manual measurement. pls make sure you do not mind before you bid. Due to the difference between different monitors, the picture may not reflect the actual color of the item.