Feature: 1. Accurate and Versatile: This monitor can detect CO2 levels ranging from 400 to 5000ppm, sampling every 1.5s, providing real time data with high accuracy, can also monitor temperature and humidity. 2. Clear Display Screen: The CO2 monitor features a user friendly display screen with adjustable brightness, allowing for easy reading of values in various lighting conditions. 3. Alarm Function: The CO2 monitor with alarm will alert you when ppm levels increase (alarm can be turned off). You can calibrate the monitor over time to maintain accuracy. 4. Long Lasting Battery: With 1000mAh rechargeable battery, this portable CO2 detector offers extended usage time, charging for 2 hours ensures up to 24 hours of continuous use. 5. Stable and Portable: The CO2 monitor is designed with a stable stand for placement on desktops, lightweight and portable, suitable for use in home, office, classroom, and other spaces. Specification: Item Type: CO2 Temperature Humidity Monitor Material: ABS CO2 Detection Range: 400-5000 ppm Temperature Detection Range: -10 to 50 Humidity Detection Range: 20%-85% RH Sample Time: 1.5 Seconds Battery: 1 x 1000mAh Rechargeable Lithium Battery (Built in). Package List: 1 x CO2 Temperature Humidity Monitor1 x User Manual1 x USB Cable