The Finger Tip Pulse Oximeter is simple and completely pain free to use. It provides a LED Display Screen of arterial oxygen saturation and heart rate. The pulse oximeter will be able to tell you your oxygen saturation levels along with your heart rate.Small beams of light pass through the blood in the finger, measuring the amount of oxygen. It does this by measuring changes of light absorption in oxygenated or deoxygenated blood. This is a painless process and generates results instantly.