Fingertip Pulse Oximeter is a portable, compact, non-invasive, measuring tool to determine the amount of oxygen the body is carrying. Attaching painlessly to a fingertip, it sends two wavelengths of light through the finger to measure pulse rate and how much oxygen is in the system. At the same time it's measuring the blood oxygen level, the oximeter also measures the pulse rate. Results are shown on a high brightness LED display that can change orientation from vertical to horizontal and back with each push of the power button. Suitable and accurate for both adult and pediatric use. Sturdy enough for hospitals and clinics as well as for in-home patients. Terrific for non-invasive spot checks of the blood oxygen level. However, please note, it is not to be used for continuous monitoring. Comes complete with the Oximeter, a lanyard, two AAA batteries and an illustrated instruction guide. Built solidly, the pulse oximeter won't require routine calibration or maintenance other than the occasional replacement of batteries. Easy to maintain and clean. Prior and after each use, wipe down the silicone area that fingers touch inside the unit with 70% isopropyl alcohol (rubbing alcohol). Case of 25.