Caution: color: we shlp according to the color of the first picture, in the package: if the quantity is not stated in the description, we will shlp the item according to the quantity and model in the title. Wintact high precision oxygen meter professional portable oxygen o2 concentration detector the product is shlpped based on the color or size of the main image of the product page. Oxygen monitor adopts high-quality gas sensors, which displays safety and reliability with accurate measurement and stable performance. It has excellent sensitivity and repeatability, easy to use and maintain, and meets the requirements by safety monitoring in industrial site for high reliability of the equipment. The shell is made of high strength engineering plastics and compound non-slip rubber, dust and explosion-proof, with high strength and smooth handfeel. Features: using high performance electrochemical sensor, with excellent sensitivity and excellent repeatability. The instrument adopts embedded micro control technology, simple operation, complete functions, high reliability. Color-screen display, user-friendly interface. There are five icon options in the main menu, namely, real-time measurement, checking record, alarm setting, system setting, and calibration. Data recording and review function, continuously record 12,000 data. Review function display bar graph and waveform easy to view data. Bilingual choices: chinese and english. Three alarm forms: sound, light and vibration. Battery power real time display. This o2 detector is applicable to the concentration of oxygen in the ambient air detection, are widely used in metallurgy, power plant, chemical, mine, tunnel, underground pipelines and other places, effective prevention of hypoxia and oxygen poisoning. Specification: color: black + red material: abs plastic test gases: oxygen concentration o2 display unit: %vol measurement range: 0~30%vol resolution: 0.1 Accuracy: ¡À5%fs data recording: 12,000 data response time 90% : less than 30 seconds alarm: sound and light vibration alarm alarm point: adjustable working voltage: dc3.7V, 1800mah battery model: lp103450-1800mah rechargeable lithium battery explosion-proof certificate no.: Cnex 18.5122 Explosion-proof mark: ex ib iib t3 gb operating conditions: -20¡«50 / -4¡«122¨H, storage conditions: -10¡«50 / 14¡«122¨H, storage case size: 255 * 188 * 63mm / 10.04 * 7.40 * 2.48In item size: approx. 138 * 71 * 49Mm / 5.44 * 2.80 * 1.93In item weight: approx. 229G / 8.09Oz package weight: approx. 795G / 28.04Oz package size: approx. 27 * 20 * 6.5Cm / 10.63 * 7.88 * 2.56In package list: 1 * o2 detector 1 * plastic pipes 1 * usb cable 1 * gas calibration cover 1 * storage box 1 * user manual english