The Oxygen Monitor Unique features - Intelligent. It is the only unit that retains its settings even when batteries are removed. - Uniquely built. It is the only unit that offers three different alarm sounds - high/low, check sensor, and low battery alarm. - Designed to endure. It has high-impact housing for best performance under the hardest conditions. - Versatile in nature. It is equipped with easy mounting bracket, soft grip sides and non-skid support feet. Two models available are standard and pediatric. - User-friendly unit. It has a backlit easy-to-read screen and straightforward keypad. - Delivers high-performance. The extremely accurate unit maintains ±1% accuracy.