... direction and eight modes low power consumption auto power off Pulse OximeterFeatures:Can be used in: hospital, home,community medical ... display, resolution 96*64Spo2: 35-99%Pulse Ratio: 30-250BPMResolution: 1% for SPO2, 1BPM for pulse ratioAccuracy: +/- 2%(70%~99%), unspecified ... (<70%)for SPO2+/- 2BPM or +/-2% (select larger) for pulse ratioPower: 1.5 V(AAA size) alkaline batteriesCan work more ...