Features: It adopts semiconductor gas sensor and air convection detection principle, can detect harmful gas in your home quickly and accurately. Multifunction air quality tester and temperature/ humidity tester: it displays CO2, formaldehyde (HCHO) and TVOC concentration, air quality indicator, temperature and humidity. 2.8-inch large LCD screen with backlight makes it clear to read even in dark environments. Foldable bracket can be placed on the desktop and is space-saving when not in use. Built-in 700mAh rechargeable battery, quick to charge it via Type-C USB cable. Portable and lightweight, easy to carry. Alarm buzzer: when the air quality is bad, the buzzer will beep, indicating that formaldehyde or CO2 concentration is seriously overshooting the standard. It detects CO2, formaldehyde and TVOC concentration in the air, can be widely used in home, car, hotel, apartment, office and more places. Note: 1. Please ventilate the new product for 2 hours and calibrate it in the open air before detecting. 2. Size and color may be slight different because of manual measurement and different light conditions. Thanks for understanding. Specifications: Color: White Material: ABS Display: 2.8" LCD Screen Principe of Gas Detection: Semiconductor Gas Sensor CO2 Detection Range: 400~5000PPM Formaldehyde (HCHO) Detection Range: 0~0.4mg/m³ TVOC Detection Range: 0~1.577mg/m³ Temperature Detection Range: 0~45& 8451;, 1& 8451; Accuracy Humidity Detection Range: 0~100% RH, 1% Accuracy Built-in Battery: 3.7V 700mAh Lithium Battery Item Size: 155 * 75 * 25mm / 6.10 * 2.95 * 0.98in Package Size: 17.5 * 12.5 * 3.5cm / 6.89 * 4.92 * 1.38in Package Weight: 150g / 5.29oz Package List: 1 * Air Quality Monitor 1 * USB Cable (Type-C) 1 * User Manual (English)