>Smal, light, convenient >SpO2,PR and Perfusion Index value display >Pulse rate value display, bar graph display >Low-voltage indication, Pulse sound, Alarm function >Auto shut off without signal after 10s >OLED display with brightness adjustable Pulse Oximeter JPD-500D Product Description 1. OLED display, brightness adjustable. 2. SpO2 Measuring Range (0%~100%, (the resolution is 1%). 3. Accuracy70%~100%:?1% ,Below 70% unspecified 4.PR Measuring Range25bpm~250bpm, (the resolution is 1bpm) 5.Accuracy?1bpm or ?1% (select larger) 6.Measurement Performance in Weak Filling Condition 7.SpO2 and pulse rate can be shown correctly when pulse resistance to surrounding light 8.Power Consumption less than 25mA 9.VoltageDC 2.6V~3.6V 10.Power Supply1.5V (AAA size) alkaline batteries ? 2