Feature: 1. Operation: There is a red button on the right side of the panel is the power button, press and hold for 3 seconds to turn on and off, and then adjust the corresponding function as needed. 2. Calibration: The air quality detector can be calibrated by pressing for 3 seconds to calibrate the sensors HCHO, TVOC, CO2. 3. Uses: Can be used for carbon dioxide detection, HCHO3 detection, tvoc detection, ambient temperature detection, humidity detection. 4. High Quality Materials: Made of high quality plastic, the air quality detector is sturdy, durable and has a long service life. 5. Real Time Environmental Assessment: Using sophisticated production technology, the air quality detector real time environmental assessment report. Specification: .Item Type: Air Quality Detector Material: Plastic Battery: Rechargeable Lithium Battery, 1200mah, 3.7V (Shipped with Built in Battery) Product Size: Approx. 12 x 7.3 x 3.5cm / 4.7 x 2.9 x 1.4in Measuring Range: CO2: 400-5000PPM HCHO: 0-1.712mg/m3 TVOC: 0-12.50mg/m3 Temperature Range: -20℃ -60℃ Humidity Range: Humidity 20-99% Weight: Approx. 208g / 7.3oz Package List: 1 x Air Quality Detector1 x USB Cable1 x User Manual