Parameters are oxygen saturation SpO2, measurement range 35-99%, resolution ± 1%, accuracy 90-99%, alarming default value > 110 bpm, upper limit setting range 100-250 bpm, lower setting range 19-95 bpm, colorful OLED display, manual alarm limit setting option, four directions display, auto power-off after 8 seconds of inactivity, accurately monitoring even in low perfusion ≤0.4%, audible and visual alarm, low voltage indicator, runs on 2 x AAA alkaline batteries, power consumption is less than 30mA, 2-month warranty.