Temperature and humidity technical indicators. When low battery is displayed, the device needs to be . Insert the included or another compatible Micro-USB charging cable into the device. Attach the other end to a USB DC charger (such as a smart phone charger) that outputs DC 5V at =1000mA. Fully charge for at least 2-3 hours before use. Avoid charging with a USB computer port which only outputs 500mA. Display method: 3.5 inch LCD display Atmospheric pressure: 86Kpa - 106Kpa Detection method for O3: Electrochemistry Sampling time: 1.5 seconds Product Size: 130*80*30MM Detection temperature: -10°C to 50°C; Relative humidity: 20% - 85% Storage temperature: -10°C to 60°C; Concentration unit for O3:ppm Power source: Lithium battery with 2000mAh capacity; 5V DC power charging via Micro-USB port Product weight: 160g/pcs This product is an air quality monitor that detects , Temperature, and Humidity. it combines sensors real-time monitoring of (O3),temperature, and humidity on its display. Features -3.5 inch LCD display -Test variables (O3),temperature, humidity -Large 2000mAh capacity Lithium battery -5V Micro-USB charging -Low battery warning O3 technical indicators Measuring range: 0-5PPM Sensor for O3: Electrochemistry Resolution: 0.001ppm Measuring range: -10-50 ° C Measurement accuracy: ±1 °C Humidity range: 20%-85% RH Measurement accuracy: ±4% RH Material: plastic colour: White Package Contents: 2 x Air Quality monitor 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.