It's currently one of the two blasters that has the maximum range.
As such, it rewards precision rather then spraying and praying.
The T-21B functions as a sort of 'designated marksman rifle', it's the closest thing to a sniper rifle one can get in-game without star cards or the DLT-19X. The T-21B can be unlocked at rank 21 for 2,500 credits.
The T-21B is designated as one of the three targeting rifles in Star Wars Battlefront.
