Four-way OLED with six display modes. Prescription required. Portable non-invasive spot check of oxygen saturation and pulse rate. Uses two AAA batteries. Low battery indicator. Comes in retail box. Easy operation auto-off feature. Lanyard silicon case and hang bag included. Child-friendly design. Adjustable brightness levels from 1 - 10. Finger size range: 0.3 - 1.0 . 2 Year Limited Warranty