Pulse oximeters measure light absorption in the finger to noninvasively monitor oxygen saturation and pulse rate. Fingertip pulse oximeters are being increasingly used for general wellness and health applications including sports, fitness, and relaxation management. Masimo MightySat Fingertip Pulse Oximeter (Bluetooth + PVI + RRp) provides the following parameters: Oxygen Saturation (SpO2) is a measure of the oxygen saturation level in the arterial blood. Higher oxygen saturation indicates more oxygen in the arterial blood. Oxygen saturation can change due to a number of factors, including lung or heart function and altitude. Pulse Rate (PR) indicates the number of pulses per minute. This parameter is useful for assessing overall fitness as well as exertion levels at a particular moment in time. Perfusion Index (PI) is the ratio of the pulsatile blood flow to the nonpulsatile blood in peripheral tissue and is used to measure peripheral blood flow. A higher PI indicates higher blood flow. Pleth Variability Index (PVI) is a measure of the dynamic changes in the perfusion index (PI) that occur during the respiratory cycle. Respiration Rate (RRp) is the number of breaths per minute. It is measured from the amplitude changes to the plethysmographic waveform. The Masimo MightySat quantifies key physiologic variables - in the morning, before or after exercise, at bedtime, or anytime you want to know if you are at your best. This product comes with Bluetooth wireless interface to the free downloadable Masimo Personal Health app and Apple Health app via your smart device. Masimo pulse oximeters are the leading brand in hospitals because they provide accurate measurements when other pulse oximeters fail by using a revolutionary invention called Signal Extraction Technology (SET ), which measures through challenging conditions including movement and low blood flow.