Integrated detection with NH3, temperature, and humidity Built-in auto calibration algorithm to enhance sensitivity and accuracy Exceeding alarm with auto detection and auto measuring; alarm can be turned off by pressing the power button twice for quiet operation Easy to use with history records saving function 3.5-inch LCD display NH3 sensor technology: electrochemical sensor Switch between Celsius and Fahrenheit temperature units 24-hour real-time monitoring Detection range: NH3 (0-50 ppm) Power supply: rechargeable 2000mAh Li-battery, including USB charging cable Material: ABS Product dimensions: 130 x 80 x 30 mm Color: as shown in image Package contents: 1 x air quality monitor, 1 x USB charging cable, 1 x user manual Only the items listed are included; other products are not included Note: Light reflection and differences in display screens may cause slight variations in color between the image and the actual item Measurement error allowance: +/- 1-3 cm