Need Help [Firmware]

Don't know whether this post is in the correct category (Sorry)

Just need help on getting K770_R8BC004_FS_APAC_RED53's (.mbn) file.
I just got K770_R8BC004_FS_APAC_RED53.fbn and I don't know what is that , I saw many of the tutorial about patches is using (.mbn)'s file.So , can anyone help me? :a011

Must use these files:

1. K770_R8BC004_MAIN_GENERIC_VI_RED53 (*.mbn)
2. K770_R8BC004_FS_APAC_RED53 (*.fbn)
3. HB1-06_Gen_CDA102568_101_R8A_GENERIC_APAC

Sorry for the late reply , but what does the .fbn do?