Feature: 1. Multifunctional Detector: A CO2 monitor is a small radar that monitors the ambient air for carbon dioxide, temperature and humidity. 2. Infrared Absorption Sensor: The carbon dioxide detector adopts infrared detection technology to more accurately determine the air quality issues. 3. Sound Light Alarm: High sensitivity NDIR CO2 sensor, CO2 sound and light alarm, monitor carbon dioxide anytime, anywhere, with mute function. 4. Clear Display: Comfortable full color display, fully adjustable high and low alarm values, realtime display of carbon dioxide concentration. 5. Wide Application: Used for air quality testing in cars, kindergartens, public places, rooms with closed doors and windows, and poorly ventilated offices. Specification: Item Type: Air Quality Monitor Material: ABS Carbon Dioxide Measurement Range: 370-9999 Temperature Measurement Range: -20-60° Humidity Measurement Range: 0-99% Temperature Accuracy: ±3℃ Humidity Accuracy: ±5% Battery: Built in 1500mAh/18500 lithium battery Working Hours: Can work continuously for more than 8 hours. Power: USB/5V Size: Approx. 80 x 80 x 55mm/3.15 x 3.15 x 1.97inWorking Time: ≥8 hours 400-450PPM (Excellent): Typical outdoor air rating. 450-700PPM (Good): Typical in a well ventilated living space. 700-1000PPM (Light Pollution): Poor ventilation living environment 1000-2000PPM (Moderate Pollution): Air rating, insufficient oxygen, lethargic, and enough to cause complaints 2000-5000PPM (Heavy Pollution): Stagnant, stale, stuffy air levels. Causes headache and drowsiness with lack of energy, decreased concentration, rapid heartbeat and mild nausea. 5000PPM Or Above (Severe Pollution): Exposure can cause severe hypoxia, permanent brain damage, coma.. Package List: 1 x Air Quality Monitor 1 x Manual1 x Connecting Cable