Accurate, fast measurement: when spo2 levels accurate to 1% between 70-100% saturation levels, pulse rate accurate to 1 bpm, 3-5s fast measurement Alarm mode: when handheld pulse oximeter show spo2 value falls below 90 or the heart rate drops below 50, the oximeter will emit an audible alarm, and the numerical value on the display will continuously flash Multi user management: pulse oximeter features an advanced 10 user mode, allowing 10 individuals to conveniently monitor, track, and store their oxygen readings on the same device, each user can record up to 300 sets of data, including date and time stamps With bluetooth function：this pulse oximeter record and store a reading up to 10 hours continuously, view real time data, graphic report and trends of blood oxygen saturation and heart rate, fingertip pulse oximeter will self switch off when a finger is removed from the unit for more than 10 seconds Package includes 1 handheld pulse oximeter, 2 probe, 1 charging base , 1 usb-c charging cable ,1 user manual. This oximeter for sports or aviation use only.