1. Multi-Functional detection: Measure CO2, Temperature, and Humidity, with high accuracy NDIR sensor, smoke 2. Real-Time Notification: Sound Warning Alarm on the device when CO2 levels reach or exceed a preset threshold. You will also be notified on your Smartphone whenever an alarm is triggered. 3. Auto-Calibration: To the accuracy of the CO2 sensor, make sure it is placed in a ventilated environment for 24 hours before being used for the first time. 4. Power Supply: Built-in 1400mAh Li-Ion rechargeable battery-powered up to 8 hours operation. Also powered with USB power or 5V Adaptor. Different batches mays result in different product appearances, printed text, and colors, which do not affect usage. PT01-C 4-in-1 Co2, temperature, humidity, smoke sensor Colour:White Material:plastic Package Contents: 1 x Co2 Detector 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.