"Cardinal Health Essentials Portable Fingertip Pulse Oximeter features a light and compact design, digital OLED screed with 10 brightness levels and 6 display modes. Easy to operate. Measures oxygen saturation levels and pulse rate with a simple fingertip design. Auto shut off after 8 seconds if not used. Includes pulse oximeter, lanyard, carrying bag, two ""AAA"" batteries and instruction manual. Not for continuous monitoring. Fingernail polish or false fingernails may cause inaccurate readings."