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