This ROM is just for the T-R42 B351_V3.2 pcba board, please don’t flash in other models.
How to know you are having the T-R42 B351_V3.2 pcba board.
first you should buy the T-R42 here:
and check the label of your back cover, it should show S/N number start with B351 as below:
and you should open the case, and check the pcba board version, you should find this
B351_V3.2 print on the PCBA board.
Download LInk: Firmware for T-R42 B351_V3.2