Features : Integrated detection with NH3/Temperature/Humidity Built-in auto calibration algorithm to enhance sensibility and save Exceeding Alarming with auto detection and auto measuring if people do not like alarm sound ,people can turn it off by pressing the power button 2 times easy operation History Records save, 3.5 inch LCD display NH3 Sensor technolology :Electrochemistry sensor Temperature unit between Celcius and Fahrenheit Switch -24 hours real time monitoring. Detection range: NH3 ( 0-50ppm) Power supply:rechargeable Li-battery 2000mah includding USB Chargeing cable Material:ABS Product Size:130 x 80 x 30MM Color: As Shown Package Contents: 1X Air Quality Monitor 1X USB charging cable 1X manual 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.