Note about MTK firmware files
The firmware files found from MTK devices differ a lot depending on manufacturer and how they were dumped.
MTK firmware files may come as just a single BIN file, while others may be split into parts. Do note that some MTK firmware files are compressed, and this compression is not fully understood. If a firmware file for an MTK phone looks like nothing but random noise in a hex editor or white noise in an audio editor, it's either compressed or encrypted from some sort of box software.
USB file transfer
This also depends from manufacturer but these kinds of phones usually show up as a mass storage device when plugged into a computer.