ACCURATE AND RELIABLE - Consistently beat other pulse oximeter in terms of accuracy and reliability during clinical tests. PLETHYMOSGRAPH AND PERFUSION INDEX - Tells you if you are taking your SpO2 and Pulse Rate properly. No more second guessing if the readings are reliable or why the pulse oximeter is not giving you a reading. NEW SOFTWARE FEATURES - 1) Auditory alarm to warn you when your SpO2 and Pulse Rate are beyond set limits. 2) Auditory Beeps for every detected pulse. 3) Adjustable brightness. SPORT ENTHUSIASTS - Suitable for mountain climbers, skiers, bikers, aviators or anyone interested in measuring their SpO2 and pulse rate while on the move. READY TO USE OUT OF THE BOX - Include 2X AAA BATTERIES and a LANYARD for convenience.