The Innovo Premium iP900BP Fingertip pulse oximeter shows your blood oxygen saturation levels (SpO2) and Pulse Rate on a OLED screen (with six multidirectional display choices). The product comes with a Plethysmograph and Perfusion Index (PI). Each wave corresponds to a heartbeat and the amplitude to the amount of blood detected in your blood vessels. When the height of the wave amplitude no longer fluctuates, this means that the pulse oximeter is now optimized and you may now take the readings. Meanwhile, the Perfusion Index informs you of the strength of your pulse. If the PI value is less than 0.2%, this means that your hands are too cold or improperly positioned in the pulse oximeter. Simply warm your finger and reposition it so that it is right under the LED lights. Comes with a lanyard and 2 AAA batteries so that you can use the pulse oximeter right out of the box. The oximeter might not work on kids or adults with small fingers. Innovo is a registered trademark of USPTO. We will actively and aggressively pursue any parties who infringe on our intellectual property rights to the maximum extent allowed by the law. Beware of Imitation, Buy Original. Innovo Pulse Oximeter is designed in USA.