Features: 5-in-1: this item is using for carbon dioxide concentration detection, thermometer and hygrometer at the same for time. Color screen: showing the current CO2 data, temperature and humidity data. The colored ring will change according to the CO2 content. Battery supply: built-in 1200mAh lithium battery, use USB charging cable to charge it. Compact and portable: can be placed in the kitchen, living room, bedroom, or take it when going out. Easy to operate: long press the "on-off" for key for 3 seconds to turn on and off. It will detect the CO2 automatically. Package Includes: 1x CO2 Meter with Battery 1x USB Charging Cable 1x Manual Specifications: Material: Plastic. CO2 Detection Range: 400-6000PPM CO2 Detection Sensitivity: 1PPM TVOC Detection Range: 0-2PPM Temp Measurement Range: 0~60C Temp Measurement Accuracy: 1C Humidity Measurement Range: 0%~99%RH Humidity measurement Accuracy: 2%RH Charging Mode: DC5V 500mA micro USB interface Battery: built-in lithium battery 1200mAh Size: 9*7*4cm/3.54*2.75*1.18 inch Screen: approx :2.75 inch Net weight: about 170g note: Please allow 1-3cm error due to manual measurement. pls make sure you do not mind before you bid. Due to the difference between different monitors, the picture may not reflect the actual color of the item.