Product Features: Portable and Accurate: This handheld oxygen (O2) detector measures oxygen content from 0-25% using an electrochemical sensor, offering high accuracy and stable performance. Fast and Precise Detection: Equipped with both sound and light alarms for immediate alert, ensuring safety in various environments. Rechargeable and Convenient: Powered by a rechargeable battery with USB charging capability, ensuring long-term usability and portability. Easy-to-Read Display: Features a large backlit LCD screen, allowing clear readings even in dark environments. Customizable Settings: Includes battery level indication, adjustable alarm values, and switchable temperature units (C/F) for personalized use. Versatile Applications: Ideal for use in factories, homes, offices, and public places, providing reliable oxygen level monitoring in various settings. Specifications: Color: Black + Blue Material: ABS Detecting Gas: Oxygen (O2) Voltage: AC 100-240V, 50/60Hz Output: DC 5V, 100050mA Measuring Range: 0~25% Resolution: 0.1% Basic Error: 5% full scale Temperature Range: -10~50 Temperature Resolution: 0.1 Working Humidity: 1% RH~99% RH Response Time: 15 seconds Recovery Time: 15 seconds Alarm Mode: Acoustic and Light Auto-Off Function: Manually selectable (auto-off after 10 minutes of inactivity) Battery: 1 * 3.7V, 1000mAh rechargeable Li-ion battery Screen Size: 4.4 * 5.3cm / 1.73 * 2.08in Item Size: 180 * 65 * 30mm / 7.09 * 2.56 * 1.18in Item Weight: 182g / 6.42oz Package Includes: 1 * Oxygen Detector 1 * USB Charging Cable 1 * User Manual 1 * Carry Bag