Restoring back to 5.1.1 Which Firmware Do I use?

For T-Mobile. Which one do I choose? It says the G920T1 is the USA T-Mobile Version

SM-G920
SM-G920T SM-G920T TMB G920TUVU2COF8 Android 5.1.1 17.07.2015 5028597 Unlock
SM-G920T SM-G920T TMB G920TUVU2COF6 Android 5.1.1 11.06.2015 5028597 Unlock

SM-G920T1
Galaxy S6 (T-Mobile USA) SM-G920T1 TMB G920T1UVU2COF9 Android 5.1.1 19.06.2015 5028597 Unlock