Usage Tips:Features:2.8 inch LCD HD color display.Display the oxygen concentration and temperature and humidity values, the curve interface.Oxygen excessive alarm buzzer sound (excessive alarm sound can be eliminated by pressing any key) + digital color change (alarm value default standard value), you can set 1%-30% alarm value.Data saving function (can store 100000 data), set timing storage, delete data, view historical data.Please note: the physical slightly color difference or difference, does not affect the use, please do not mind, thank you!The display brightness adjustment 5%-, the default brightness of 60%, 10 seconds after the screen saver minimum brightness, any key can be restored to 60% brightness.Celsius C and Fahrenheit F switch, long the / key to switch.Specifications:Model: A8Material: ABSDisplay Method: 2.8 inch TFT full color LED backlight LCD screenOxygen Measurement Range: 0-30%VOLOxygen Resolution: 0.1%Temperature Measurement Range: -9~55Humidity Measurement Range: 0%RH~RHLithium Battery Capacity: 2500mAhStandard Charging Voltage: 5.00.5VColor: As shownPackage Contents:1 x Handheld Oxygen Concentration DetectorOnly 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.