Xiaomi recently announced its smart Door and Window Sensor 2 for the Chinese market. The US$7 smart sensor carries forward the tech giant's kitchen sink approach to tech releases, and is in sharp contrast to its recent release of the massive, expensive 98-in Smart TV Max.
https://www.notebookcheck.net/What-s-next-for-Xiaomi-After-the-98-in-US-3000-Smart-TV-Max-apparently-the-US-7-Door-and-Window-Sensor-2-for-slightly-smarter-smart-homes.484875.0.html