RSD5500 Fingertip Pulse Oximeter Details： Features:                                                    1.Display Mode:OLED display  2.SpO2 Measuring Range:0%~100%, (the resolution is 1%). 3.Accuracy:70%~100%:±2% ,Below 70% unspecified. 4.PR Measuring Range:30bpm~250bpm, (the resolution is 1bpm) 5.Accuracy:±2bpm or ±2% (select larger) 6.Resistance to surrounding light: The deviation between the 7.value measured in the condition of man-made light or indoor 8.natural light and that of darkroom is less than ±1%. 9.Power Consumption:less than 25mA 10.Voltage:DC 2.6V~3.6V 11.Power Supply:1.5V (AAA size) alkaline batteries * 2 12.Safety Type:Interior Battery,BF Type   Packing information:                                 1 hanging rope 1 user manual Physical Identity Weight:About 75g Machine Dimension:58(L) * 30W) * 30(H) mm Box volume:10*9*4cm Outer box volume:47.5cmx37cmx21cm