It is a handheld Oxygen Detector,equipped with advanced sensor technology, precisely measure the oxygen content in the environment within a wide range. it is portable,along with a comfortable hand grip, allows you to carry the Handheld Oxygen Detector wherever needed with ease. The simple and intuitive operation interface and clear button settings make it effortless for even novice users to get started. Just turn it on and start measuring, with real-time display of oxygen concentration,temperature, humidity, enabling you to stay informed of the environmental conditions at all times. When the oxygen concentration is below the safety range you set, it will sound an alarm to remind you to take corresponding safety measures Product name: Oxygen detector Display method: LCD display Measurement items:02,Temperature,Humidity Detection method of 02: Electrochemical Unit of 02 concentration: %Vo 02 Measuring range: 0-30.0% of volume Atmospheric pressure: 12.5 psi - 15.4 psi Sampling time: 1.5 seconds Temperature range: -10°C-50°C (14°F-122°F) Storage Temperature: -10°C-60°C (14°F-140°F) Relative Humidity: 20%-85% Humidity range: 20%-85% Power: 1500 mAh rechargeable lithium battery. Rechargeable 5V DC power supply via USB port Product Dimensions: 16.1x7.7x3.3cm Product weight: 265g Common sense of life - the effects of hypoxia and oxygen enrichment on the human body 100%: Fatal, 6 minutes confined environment 50%: Fatal, 45 minutes with treatment, confined environment Greater than 23%: Oxygen-enriched 20.9%: Normal oxygen concentration 19.5%: minimum allowable oxygen concentration 15-19%: Reduces work efficiency, can cause head and circulatory problems 10-12%: shortness of breath, loss of judgment, purple lips 8-10%: loss of intelligence, faint