1. and high quality. 2. Appearance of light and novel, easy to carry, easy to operate 3. Menu operation interface, battery power real time. 4. Sound, light and vibration alarm 5. There is a kind of essential safety instrument which can continuously detect the oxygen concentration in the working environment Widely used in metallurgy,power plant, chemical, mine, tunnel, underground pipelines and other places, effective prevention of hypoxia and oxygen poisoning. Condition: Model:803 Sensor:Electrochemical Principle Detection Gas:Oxygen O2 Temperature Measurement:Ambient Temperature Display Unit:O2: %VOL Temperature:℃/℉ Range:O2: 0-25%VOL Temperature:-15-50℃ Resolution:O2: 0.1% VOL Temperature:0.1℃-0.1℉ Response Time:T90 Less Than 15s Alarm: sound and light alarm Alarm Point: low alarm point 19.5%VOL High alarm point 23.5%VOL Battery Type:3 x AAA alkaline batteries(not included) Operating Temperature: -10-+50℃ Operation Humidity: 15%-95%RH(no condensation) Weight: . 176g/6.2oz Color:Blue Material:Metal+Plastic Package Contents: 1 * Gas leak detector 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.