Mi Box  is similar to YUNDOO Y6 in size and function. Pls check the video to see difference.

https://youtu.be/SnISAcgdtPg

Mi Box,4K Android TVTM set-top box HDR video support Bluetooth voice remote included US $ 69.

YUNDOO Y6 is a Super-Mini Android TV Box, very small and smart. This streaming Media Player is powered by Quad core Amlogic S905X Cortex A53, includes a Penta-Core (5-core) GPU that can reach speeds of up to 2.0GHz.

Source from here.