ACCURATE AND RELIABLE - The Zacurate 500E Pulse oximeter is the premium model of the Zacurate line of pulse oximeters. With a vastly improved LED and sensor, it allows SpO2 (Blood Oxygen Saturation level) and pulse rate measurement even at low blood perfusion. MEET & EXCEED FDA STANDARDS - Designed for sports enthusiasts like mountain climbers, skiers, bikers or people interested in measuring their SpO2 and pulse rate. In addition, although FDA only requires pulse oximeters to have SpO2 accuracy of ±2%, the 500E pulse oximeter barely deviates more than 1% under lab conditions. PATENTED MULTI-DIRECTIONAL DISPLAY – Choose from 6 different layout options for convenient viewing of your blood oxygen level and pulse measurement. At the push of a button, switch the OLED display from facing the user to another layout facing your caregiver.