What is the drainage function on the Xiaomi Watch S4?

Here are more details about the drainage function on the Xiaomi Watch S4:
1. The principle of the drainage function is to play a sound of a specific frequency to make the speaker vibrate and use the vibration to drain the water that has invaded the speaker, thus protecting the speaker from being corroded by water;
2. The drainage function can be used when the speaker of the watch is flooded after swimming or in daily life;
3. You can press the lower button on the homepage of the watch to enter the dashboard and tap the drainage icon;
4. After swimming, the watch will enable the drainage function automatically.