Common Display screen Test variables: carbon dioxide (CO2), temperature, humidity 2200mAh capacity Lithium battery 5V -USB charging Low battery warning Specifications: Display : Common Display Screen Pressure: 86Kpa - 106Kpa Sampling time: 1.5 seconds temperature: -10 c to 60 c CO2 Concentration Unit: PPM source: Lithium battery with a capacity of 2000mAh DC 5V supply via -USB port Instructions: 1. When you long press the button, the quality monitor will . 2.About Charge When the low battery is displayed, the device needs to be charged. Insert the included or another -USB charging cable into the device. Attach the other end to a USB DC charger (such as a smart phone charger) which outputs DC 5V at more than = 1000mA. Charge fully for at least 2-3 hours before . Avoid charging with a USB computer port which only outputs 500mA. 3. Parameters Carbon Dioxide Monitor Indicators Measuring range: 400-5000PPM Resolution: 1 PPM Measuring range: -10-50 c Technical temperature and humidity indicators Humidity range: 20 percent -85 percent RH Measurement accuracy: 1 c Measurement accuracy: 4 percent rh CO2 sensor: infrared (NDIR) Colour: black Material: ABS Package Contents: 1 x Quality Monitor 1 x English manual Only the above package content, other products are not included. Note: Light and different displays may the color of the item in the a little different from the real thing. The measurement allowed error is 1-3cm.