Features:1. 100% brand new and high quality. 2. Appearance of light and novel, easy to carry, easy to operate3. Menu operation interface, battery power real time.4. Sound, light and vibration alarm5. There is a kind of essential safety instrument which can continuously detect the oxygen concentration in the working environment6. Widely used in metallurgy,power plant, chemical, mine, tunnel, undergroundpipelines and other places, effective prevention of hypoxia and oxygen poisoning.Specification:Condition: 100% Brand NewModel: 803Sensor: Electrochemical PrincipleDetection Gas: Oxygen O2Temperature Measurement: Ambient TemperatureDisplay Unit: O2: %VOL Temperature: /Range: O2: 0~25%VOL Temperature: -15~50Resolution: O2: 0.1% VOL Temperature: 0.1-0.1Response Time: T90 Less Than 15sAlarm: sound and light alarmAlarm Point: low alarm point 19.5%VOL High alarm point 23.5%VOLBattery Type: 3 * AAA/7 alkaline batteries(not included)Operating Temperature: -10~+50Operation Humidity: 15%-95%RH(no condensation)Weight: Approx. 176g / 6.2ozPackage List:1 * Oxygen Gas DetectorNote:1. Improper operation or inappropriate use of the environment may weaken the operating performance of the instrument. For the safest and most effective use of the instrument, please read the following correct operating procedures and safety 2. Please read the operation manual carefully before any operation is performed.3. The window and filter membrane of the sensor must be kept clean. If the sensor window is blocked or filtered by the water film, it may result in a reading below the actual gas concentration4. Tho replacement of batteries, maintenance parts and other operations can only be carried out in a safe environment.5. In order to ensure the safety and the proper use of the instrument, the operation and maintenance of the instrument can only be carried out by qualified personnel.6. Every day before use please check the accuracy of the instrument in the fresh air, ensure that the measurement error is within the allowable range. If it exceeds the allowable error range, the instrument must be calibrated.7. Keep the alarm through the mouth dean, no foreign objects clogging, otherwise it will lead to not hear the alarm or alarm information identification8. Removing and replacing the battery must be performed in a known, no hazardous environment.