Features: • Temperature difference compensation calibration technology, judge the ambient temperature data, automatic calibration test results. • You can measure CO2 levels, care about your family's health. • Locate the source of the contamination and test it more accurately. • It can be connected to mobile power to check the sealing space. • Long-term record, tracking formaldehyde /TVOC concentration trend. • It can be used in greenhouse plantation, farm indoor air detection, household air detection and so on. Basic parameters: All test data are derived from laboratory data, and the use values may be slightly different due to specific environments Power supply: USB 5V Connection method: Power Bluetooth 4.0 System requirements: iOS 9.0 or above/Android 4.3 or above TVOC detection range: 0~9.999 mg/m3 at a temperature of 5-35℃ HCHO detection range: 0~1.999 mg/m3 at 5-35℃ CO2 detection range: 400~2000ppm Temperature detection range: -10~+50℃ Product size: 75*50mm Product weight: 74g Package size: 116 * 95 * 56mm / 4.6 * 3.7 * 2.2in Package weight: 110g / 3.9 ounce