Easy to use: this finger pulse oximeter designed with one button control which makes measurement more convenient and easier, users just need to put one of his fingers into the fingertip photoelectric sensor for measurement, then the screen will directly show the result clearly, the oxygen level monitor automatically powers off after 10 seconds of inactivity, making the experience safer and more environmentally friendly Accurate and reliable: our oxygen blood monitor can accurately determine your spo2 blood oxygen saturation levels in 10 seconds and oled display make this finger oxygen monitors very easy to read Easy to carry: this oxygen level monitor are very light and small size, convenient in carrying, also it comes with a detachable lanyard which can measure your oxygen saturation anywhere Two aaa batteries power supply design: 2 aaa batteries power supply also use the aaa batteries to supply power at any time anywhere You will get: 1 x fingertip pulse oximeter, 2 x aaa batteries, 1 x lanyard, 1 x user manual