50DL Display Information: The Pulse Oxygen Saturation (SPO2) Pulse Rate (bpm) Pulse Intensity (bar-graph) SPO2 Parameter Specification: Measuring Range: 0%-100%, (the resolution is 1%) Accuracy: ± 2% in stage of 70%-100% SpO2, and meaningless when stage being smaller than 70%. Optical sensor: Red light (wavelength is 660nm, 6.65mW) Infrared (wavelength is 880nm, 6.75mW) Pulse Parameter Specification: Measuring Range: 30bpm-250bpm, (the resolution is 1bpm) Accuracy: ± 2 bpm or ± 2% (select larger) for Pulse Rate Pulse Intensity: Range: continuous bar-graph display Battery Requirement: 2 x 1.5V AAA alkaline battery Battery Useful Life: The two batteries can work continually 30 hours Dimensions and Weight: Dimensions: 57(L) x 31(W) x 32(H) mm Weight: 50g (with the batteries) Display Mode: 2-digit digital LED display Bar-graph OLED display