Small in size, and easy to carry Color OLED monitor, 4 different display modes Pulse histogram and 4 kinds Spo2 wave display Easy to use & high accuracy and repetition Low voltage alarm display Pulse oximeter perfusion index (PI) Auto power-off after 20 seconds without signal Runs on standard AAA batteries and continuous working time is 30 hours Light weight of 55g, batteries included Alarm setting: (SpO2 Hi/Lo) (PR Hi/Lo)