Features:Measure SpO2 and PR accuratelyLED display for SpO2 value and PR value， bargraph displayLow battery voltage indicatorAutomatic power off when signal is not available for 4 seconds2 AAA batteries support 30 hours continuouslyMini size， light weight， convenient to carryWidely used in hospital， home healthcare， oxygen bar， community medical centre， alpine area， sports healthcare etc.Specification:DisplayLED displaySpO2Measurement range: 35��99%Resolution: ��1%Accuracy: ��2% (70%��99%)， unspecified (<70%)Pulse rateMeasurement range: 30��255 bpmResolution: ��1%Accuracy: ��2bpm or ��2% (select larger)Power1.5V (AAA size) alkaline battery x 2Supply voltage: 2.6~3.6VWorking current��20mAInterference resistance against ambient lightDeviation between SpO2 in nature indoor lighting condition and in dark room is less than ��1%Dimension & Weight57 (L) �� 31(W) �� 32(H) mm50g (with batteries)