Feature: 1. It can accurately detect indoor formaldehyde (HCHO), total volatile organic compounds (TVOC) and air quality index (AQI, 6 levels in total). 2. You can more easily monitor the air quality in your home, car, hotel room, or wherever you live. 3. Using semiconductor air quality sensor technology, diagonally backlit LCD screen. 4. One‑button detection, automatic shutdown function, over‑range alarm system. 5. Easy to use, you just need to press two AA alkaline batteries to use, which is very practical. Specification: Item Type: Formaldehyde Detector Material: ABS Purpose: to detect the methanol content in the air Working Voltage: 2.4~3.2V Detection range: 0.000-3.888mg/m³ (formaldehyde), 0.000-9.999mg/m³ (TVOC) Product Size: Approx. 53x118x21mm / 2.1x4.6x0.8in Color: White Battery Model: L6/AA Battery Type: AA Alkaline Battery (Battery Included) Battery Capacity: 1500mAh Number of Battery: 2. Package List: 1 x Formaldehyde Detector2 x Battery Note: Do not use it outside the current and voltage range.