Long to power on, short to switch to Fahrenheit, 5 times consecutively to calibrate the sensor Long to enter standby mode, short to turn off the buzzer alarm Real-time temperature, humidity, and concentration values; battery level, alarm status TYPE-C charging port concentration indicato Since this product has a built-in electrochemical sensor, please note the interference fromother gases on the sensor readings. For every 100PPM of the following gases. thecorresponding reading is affected as follows. Hydrogen sulfide:-20PPM Nitrogen dioxide:110PPM Chlorine gas:90PPM dioxide:5PPM Nitric oxide:2PPM Carbon monoxide,ammonia, hydrogen, carbon dioxide: 0PPM Color:As Shown Material:Aluminum Alloy Package Contents: 1 * Analyzer 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.