Specification:Finger oximeter. Pulse oximetry transducer properly placed on a finger. Fold the oximeter. over the end of the digit.A pulse oximeter works by passing a beam of red and infrared light through a pulsating capillary bed. The ratio of red to infrared blood light transmitted gives a measure of the oxygen saturation of the blood.Fingertip Pulse Oximeter with alarm is designed to provide an affordable yet accurate way for spot-checking blood oxygen saturation levels and pulse rate.Pulse oximetry is a noninvasive method for monitoring a person's oxygen saturation (SO2). Though its reading of SpO2 (peripheral oxygen saturation) is not always identical to the more desirable reading of SaO2 (arterial oxygen saturation) from arterial blood gas analysis, the two are correlated well enough that the safe, convenient, noninvasive, inexpensive pulse oximetry method is valuable for measuring oxygen saturation in clinical use.