Uses high-precision TVOC semiconductor sensors, with stable working performance, can accurately detect the carbon dioxide value. Adopts electrochemical detection module with stable detection performance, anti-jamming ability, low consumption, and can provide long service time. Large LED display, you can clearly see the amount of electricity, CO2 value, TVOC value, HCHO value, temperature and humidity. and switchable, real-time detection, automatic data refresh, with multi-use. Adopts air convection design, which can provide more accurate detection results. Equipped with an air quality level division function, three different colors correspond to different air quality levels, allowing you to know the current atmospheric conditions more accurately and graphically. About Shipping: All items will be shipped within 3 business days after the payment is received. Most times you will receive them within 8-12 days then. The specific delivery time is depend on circumstances.Any questions, please feel free to contact us During the shopping process, if you have any questions, please feel free to consult us, we will reply you within 24 hours, wish you a happy shopping Thanks for your cooperation and well make you feel satisfied.