The Zacurate 500C Elite Fingertip Pulse Oximeter is manufactured according to the CE and FDA standards set for pulse sports and aviation oximeters It shows your measured SpO2 and pulse rate on a high quality OLED screen and features an additional plethysmograph that measures your pulse strength. Other features include 1) Auditory alarm to warn you when your SpO2 and Pulse Rate are beyond set limits. 2) Auditory Beeps for every detected pulse. 3) Adjustable display brightness. 4) OLED screen with plethysmograph. Zacurate 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 law. Beware of Imitation, Buy Original. Zacurate Pulse Oximeter is designed in USA. Intended use for spot check of pulse rates and blood oxygen saturation level at home, in sport and recreational use, such as mountain climbing, high-altitude activities and running. This device is for Sports & Aviation use only and is not a medical device.