Accurate and Reliable - Metene 20E pulse oximeter is used to accurately measure both SpO2 and pulse rate, and display it conveniently on a large OLED display. You can always be sure of a reliable measurement. New Software Features - (1) The function of oxygen finger monitor tells you if you are taking your SpO2 and Pulse Rate properly. (2) Auditory alarm to warn you when your SpO2 and Pulse Rate is beyond set limits. (3) Adjustable display brightness. Easy to Use - The pulse oximetry finger monitor is a simple operation with 1 button which can be easy to take a reading and it will automatically power off after 10 seconds. Sport/Health Enthusiasts - Suitable for mountain climbers, skiers, bikers, aviators, or anyone interested in measuring their SpO2 and pulse rate while on the move. You should only use the pulse oximeter before or after your exercise. Also, you must remain stationary while the pulse oximeter measures your pulse and SpO2. Accessories & Warranty - Lightweight and small size with a Lanyard for convenience and include 2X AAA Batteries.