PROFESSIONAL DETECTOR -- Portable (O2) gas detector, measure ran 0-25% content. Adopt electri-chemical type gas sensor to measure, this detector sensor with stable performance and high accuracy. ADJUSTABLE ALARM -- Sound and light dual-alarm when O2 gas concentration reaches the level of the alarm. And the alarm value can be customized according to users demands. BACKLIT LCD DISPLAY -- The gas meter is compact and lightweight, features a lar LCD display with backlight, you can t the result from the screen at a glance, even in dark,easy to carry on and convenient for reading. USB RECHARABLE -- Come with a 3.7V recharable lithium battery, charging through micro USB interface, which can be powered by power adapter, power bank, etc.. WIDELY APPLICABLE -- The detectorCs can be used in metallurgy, power plant, chemical, mine, tunnel, underground pipelines and other places, effective prevention of hypoxia and, Manufacturer: SLZJWLPPA