Bullet Points:  1. Real-time and accurate monitoring of CO2 concentration, PM1.0, PM2.5, TVOC, ambient humidity, and temperature values.  2. Together we can intelligently control the ventilation system, and at the same time can connect to WIFI to view the recorded data on the mobile phone.  3. Intelligent color screen display, the numbers are clear, easy to identify and read.  4. In alert mode, alert the user to the environment by changing the color.  5. When the CO2 concentration exceeds the value of 1500PPM, an alarm will be issued to notify you to keep the indoor environment ventilated in time.         6 IN 1: Measure PM2.5, PM1.0, TVOC, CO2, Temperature, and Humidity, with a sensitive laser particle sensor, laser TVOC sensor, and accurate NDIR CO2 sensor.        Automatic & Manual Calibration: Offer two calibration modes, Manual Calibration, and Automatic Calibration. We have calibrated it manually in the factory, and it can automatically calibrate during the detection.       Wi-Fi Enabled & APP Smart Control: Smart PT02 can connect to the Internet, works seamlessly with Tuya App, Set alerts, receiving air quality measurements anytime and anywhere.       Wireless IoT Controller: Create a Smart Scene in the Tuya app, make PT02 control the Smart home appliances. First, you should add Smart PT02 and other Smart home appliances to Tuya APP. Then set the conditions. The PT02 monitor will activate Smart Fans, Air Purifiers, or other appliances in response to changes in your home's air quality.       Supports RS485/Relays Signal Output: The RS485 port and Relay port are located on the rear of the device. And the RS485 supports data export. The Relays can control the appliances directly (This function is only recommended for professional personnel or engineers.)           Specification:  Product Name: Smart Air Quality Monitor  Temperature measurement range: -20°C~60°C; ±2°C  Humidity measurement range: 5%~95%RH; ±5%RH  CO2 measurement range: 400-5000ppm, resolution: 1ppm  CO2 measurement accuracy: ±50ppm or ±5% of reading  TVOC measurement range: 0& 65374;20mg/m3  PM1.0 measuring range: 0& 65374;500μg/m3  PM2.5 measurement range: 0& 65374;500μg/m3  Working temperature: 0°-50°C  Working humidity: 0-95% (non-condensing)  Input voltage: DC 12V/2A  Material ABS+LCD  Product weight and size: length, width, and height 18*12*4cm/7*4.7*1.6inch  Single output wiring: RS485/relay for CO2, TVOC, PM1.0, PM2.5, and humidity signal output    Packing List:  Carbon dioxide detection instrument*1  Manual*1    Notes:   Due to the lighting effects and shooting angles, there is a color difference in the product, please understand.   Due to manual measurement, there is slight tolerance in the product size.