The Fingertip Pulse Oximeter is intended for measuring functional oxygen saturation of arterial hemoglobin (SpO2) and pulse rate for both adults and adolescents. This device is to be used for non-invasive spot checking in the home and professional caring environment. It is designed for fingers between 7mm and 25.4mm in diameter (0.28 inches to 1.0 inches). This device is not intended to be used under motion or low perfusion scenarios. Features: Small and lightweight design. Plethysmograph and Perfusion Index for accurate SpO2 and Pulse Rate readings. One button control for ease of use. Automatic power-off. Accurately determine your SpO2 blood oxygen saturation levels in 10 seconds Easy to read OLED display