3 Color Status Indicator: With multiple alarm, there is 3-color Light Indicator and 3 Facial Comfort (1500~5000 ppm with bad , red light; 700-1500 ppm with normal , yellow light; 0-700 ppm with good , green light. You Can Intuitively Understand The Air Quality You Breathe. 3-in-1 Air Quality Monitor Data: Detect CO2, Temperature and Humidity. CO2 measuring function, the high-precision thermometer and hygrometer can also be used to monitor indoor temperature and humidity in real time. It is an indispensable device or office. High Accuracy CO2 Sensor: Built in infrared sensors that can accurate detect air of Carbon Dioxide(CO2). uses non-dispersive infrared technology (NDIR), Full temperature range correction, high measurement accuracy, fast response, resolution up to 1 ppm, measuring range up to 0 to 5000 ppm. USB Rechargeable: Rechargeable lithium battery with a capacity of 2400 mAh, standby for 18 hours, it supports USB charging and battery indicator, which is a good solution for your testing needs in a different environment for a long time. Product name:Carbon dioxide monitor Model:PTH-5 CO2:400-5000PPM Accuracy:50PPM 6% Temperature:-10~40 Humidity:20-80% Power-supply:2400mAh lithium battery Colour:black Material:plastic Package Contents: 1 x CO2 sensor 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.