Safely and accurately measures oxygen saturation of arterial hemoglobin and pulse rate. Displays blood-oxygen saturation (SpO2), pulse rate, and pulse bar. Four display modes with adjustable brightness. Dual-color OLED display with adjustable screen brightness. Fits a wide range of finger sizes, from pediatric to adult. Features low battery indicator and automatic shut-off to conserve battery power. Includes adjustable neck strap with quick-release lanyard. Requires two "AAA" batteries (included). Two-year limited warranty.