MD300CH3 is a very important and common device to check oxygen saturation (SpO2) and pulse rate. As a small, compact, simple, reliable and durable physiological monitoring device, Fingertip pulse oximeter is widely applied in clinic, hospital, social medical organization, first aid and homecare etc. Accurate Measurement Professional Guarantee 1. Convenient to operate: Auto power on/off, one key handle; 2. Low power consumption: 2 AAA-size alkaline batteries can continuously use up to 30 hours; 3. Bright OLED display, 6 display modes, SpO2 and Pulse Rate can be read from any angles, no matter day or night;