This product is a professional multi-parameter indoor air quality (IAQ) and ventilation inspection set launched by Testo, Germany, which integrates Bluetooth wireless transmission, high-precision CO2 / temperature and humidity / thermal sweep measurement, data logging and Intelligent Analysis, designed for air quality monitoring, ventilation system commissioning, the assessment of the thermal environment in scenarios such as office, commerce, industry, ventilation and others, for effective, practical and on-site data measurement and management.