If you are considering flashing this firmware, here are the changes you can expect compared to the ISP-locked stock version:
Even in stock firmware, try:
Many ISP firmwares leave backdoors.
The decision comes down to your technical comfort level.
Not all ZXHN H108N V25 units are equal. Hardware revisions matter critically. zte zxhn h108n v25 firmware original patched
Action steps:
If the upgrade fails with "Invalid image", your bootloader rejects unsigned code. Use Method B. If you are considering flashing this firmware, here
MD5: 5f4d7c2b9a1e6f0d8c3b7a2e1f6d0c8b
File: ZTE_H108N_V25_patched_by_MACRON.bin
Size: 4,194,304 bytes
Never flash a .bin larger than your flash size – that is a guaranteed brick.