Feature:1. The large screen displays the measurement results, and you can get the oxygen concentration at a glance.2. The gas detector can warn the operator in the area where the leakage occurs, giving them a chance to leave.3. It is widely used in chemical industry, electronic industry, underground operation, oxygen detection in car.4. With maximum/minimum hold function, used to measure absolute high/low peak values and hold data.5. It has been widely used in industry and can be used to monitor manufacturing processes and emerging technologies in some places.Specification:Item Type: Oxygen MonitorMaterial: ABSMeasuring Range: 0~25% volumeMaximum Overload: 30% oxygenResponse Time: <15sSensor Type: Electromagnetic oxygen sensorUse Environment Humidity: 15~90%RHPower Supply: 3x1.5V AAA battery (Not included)How to Use:Get the product, open the back cover, install the battery, and press the power button to turn it on. Press the power button to turn on the screen. The hold button means stop working, and the up and down buttons switch between the maximum and minimum values.Function:1. Data hold2. Maximum/Minimum3. The unit switch unit is between volume percentage and ppm, (mg/m^3)4. Alarm settings5. Calibration6. On/off (time off).Package List:1 x Oxygen Monitor(Battery Not Included)1 x Black Box1 x Instruction Manual