Features: 1.[PREMIUM DETECTOR]This multifunctional air quality detector can accurately detect the current CO2 concentration,temperature, and humidity in the air. It can help you understand indoor air quality at a glance. 2.[CO2 CONCENTRATION STAGE SOUND AL ARM] This CO2 detector is designed with 3 stages of CO2 concentration-normal stage (0-800 ppm), warning stage (800-1200 ppm), and dangerous stage (1 200-5000 ppm). It will alarm you when thedetected CO2 concentration is beyond the safe value you customized. 3.[CONVENIENT CAL IBRATION] To ensure the accuracy of measurement, this CO2 monitor supports the calibration function.Press One buttons three times in an open environment and let it stand for 200 seconds to calibrate this CO2 meter easily. 4.[WIDE APPLICATION] A hanging hole is designed on the back of this portable CO2 detector so that you can hang it up to the wall for easy viewing. The indoor CO2 meter is ideal for use in grow room, offices, kitchens, schools, kitchens,schools cellars,and cars. Product Description: WiFi Smart CO2 Detector Power:5V1AC02 Sensor:400-5000PPm Accuracy:(50ppm+5%reading value) Humidity sensor:0-100%RHAccuracy2%RH(25?) Working Temperature:-10?~+50?0~95%RH -10~+65?accuracy+0.3? Communication protocol:WiFi Default CO2 alarm level (Unit: ppm) : 1. (CO2 800) no alarm, display smiling face to remind that the ernvironmental CO2 concentration is low and the living environment is comfortable 2. (800 CO2 1200) no alarm, smiling expression indicates that the ervironmental CO2 concentration is moderate 3. (1200 CO2 1500) no alarm, uncomfortable expression indicates that the ervironment is not good enough 4. (1500 CO2 3500) the alarm sound (drip, drip, drip) sounds three times, indicating that the CO2 concentration is relatively high and it is not suitable for people to live 5. (3500 CO2 5000) the alarm sound (drip, drip, drip, drip, drip) sounds 6 times, indicating that the CO2 concentration is very high. Please pay attention to environmental safety 6. (5000 CO2) when the concentration reaches 5000, the buzzer keeps alarming,indicating that the CO2 concentration is extremely high and the ervironment is dangerous Note: 1. Please make sure to use 5V 1A output power to supply it ,or the device would be burned off.2.Product has built-in sensor that support high precision detection datas. Package Included:1*WiFi Smart CO2 detector, 1*instructions, 1*USB FQA: Q: What type of CO2 sensor is used? A: MH-Z19C carbon dioxide gas sensor and AHT20 temperature and humidity sensor. Q: The accuracy of CO2 sensor? A: (50ppm+5% * reading)/0.3?/2% RH Q: Under what circumstances will CO2 sensor call the police? How to call the police? A: There are three ways, one is mobile app; One is that a buzzer will sound in the fuselage, and the maximum buzzer value is 80dB; One is that there will be a red warning on the display. Q: Does the equipment have a calibration function? A: The equipment will be calibrated once a day. Q: What is the detection range of CO2 sensor? A: According to the Co2 concentration, if it exceeds 3500PPM, it will alarm. We can define this value. Q: How to supply electricity? A: The body has Type-C, which is directly powered by USB cable +USB power supply. Because WIFI consumes electricity and needs to be recharged every few hours, we use USB cable for direct power supply.