Come and see our amazing products. This product has been fine-tuned, and can accurately measure human blood oxygen saturation (Sp02), pulse rate (heart rate), and display 4 kinds of data or graph: oxygen level, pulse rate, pulse rate bar graph, pulse rate waveform.Streamlined design, small weight and pocket-size. You can monitor anytime, anywhere. Please be sure to use the product in a stationary state.Press the button for about 0.5 seconds, wait for 8-10 seconds after turning on the device, and then it can measure the data. Please install the batteries according to the positive and negative symbols displayed on the device, this is very important.The device will automatically shut down after 8 seconds of inactivity to avoid battery drain due to forgetting to shut down. Pls confirm further with us if any query about packing info, inventory status and time schedule.