Specifications: Material: ABS+PC Battery: 1 * built-in lithium battery Display: LCD Recharging interface: Type-C Working current: 150mAh Standby current: 80mA CO2 measuring ranges: 400ppm-5000ppm Temperature measurement ranges: 0& 8451; to 70& 8451; Humidity measurement ranges: 0%RH-100%RH CO2 alarm value: & 65310;1800PPM, last 5s Item size: 98 * 66 * 30mm / 3.86 * 2.60 * 1.18in Item weight: 120g / 4.23ounce Package size: 110 * 75 * 40mm / 4.33 * 2.95 * 1.57in Package weight: 210g / 7.41ounce Features: Compact in size, lightweight and portable, easy to take out and carry around with you. Uses high accuracy NDIR sensors, with stable working performance, can accurately detect carbon dioxide value. Adopts electrochemical detection module with stable detection performance, anti-interference ability, low consumption and can provides long service time. 3.5inch large LCD display, you can see the electricity quantity, CO2 value, temperature, and humidity clearly. & 8451; and & 8457; switchable, real-time detection, automatic refresh data, with multi-use. Adopts air convection design, which can provides more accurate detection results. Equipped with air quality level division function, three different colors correspond to different air quality levels, allowing you to more accurately and more graphic know the current air conditions. Green indicates 400-800ppm, yellow indicates 800-1800PPM, red indicates 1800-5000PPM (1800PPM) and the alarm will starts, and the alarm will last for 5 seconds. The product does not need calibration, it can be tested after booting, and it can accurately detect carbon dioxide. Multiple ventilation holes reserved on the housing not only accelerate the convection between the air and the machine, thereby realizing effective detection, but also provide a fine heat dissipation effect. Widely applications: agricultural planting, greenhouse vegetables, production warehouse, material processing, home interior, business offices, and etc