Features: USB CHARGING: The O3 detector is equipped with a USB charging port and a high capacity 2000mAh lithium battery that warns when the battery is running low. CLEAR SCREEN: O3 detector adopts color LCD, high definition pixels, easy to view, support time and date, self calibration function. O3 DETECTOR: User adjustable O3 alarm threshold, which will sound when the threshold is reached to alert the user of elevated concentrations. ACCURATE READINGS: Built in electrochemical sensors, temperature and humidity sensors, and an on board fan that draws in surrounding air for more accurate real time results. SMALL AND PORTABLE: The small size and light weight of the O3 detector makes it very convenient to carry around so that you can monitor the O3 concentration in the air at any time. Material: ABS Color: White 3.5 inch TFT LCD screen O3 Technology: Electrochemical Sensors examination range: (0-500) O3 (0.000-5.000ppm/M3) Package Contents: 1X O3 Air Quality Monitor 1X USB charging cable 1X manual Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.