Huami is a wearables OEM that has recently made a name for its own brand, Amazfit. Besides this, it also has a role as an ODM to other brands such as Xiaomi to make their smart accessories. The company has reported a year-on-year (YoY) growth of no less than 72.4% in terms of shipments for 2019.
https://www.notebookcheck.net/Huami-reports-that-it-made-nearly-US-835-million-in-2019.457521.0.html