1.This is our newly developed blood oximeter, with an alarm function added. The new product has a very low price and good quality. 2.Can set alarm function (SPO2 PR). The upper and lower limits of the value can be adjusted. If the set value is exceeded, the product will give an audible alarm and the screen will flash 3.The font is enlarged and bold. The fonts are bigger and clearer than other sellers, even the elderly can see them clearly 4.Easy to Read-Large fonts digital OLED display; low power indication; SpO2, PR, Pulse Rate bar graph display, easy to track changes in blood oxygen saturation and pulse rate. 5.Accurate And Reliable-Accurately determine your SpO2 (blood oxygen saturation levels), pulse rate and pulse strength. 6.PI Indicator: Perfusion Index. It reflects the amount of blood flow being measured by the oximeter. A health care professional tests blood flow to establish norms and aid in identifying changes in a patient's condition. 7.Multi-direction Display: Rotatable multidirectional display. 4 directions, 6 modes, allow you to view your results in any direction. 8.Automatic shutdown: 8 seconds after you remove your finger, it automatically shuts down to save energy consumption. 9.Comfortable to wear: Built-in soft and comfortable silicone finger mold, without pressing the tip of the finger, the measurement is more accurate.