The T-3 represented a specific droid type that saw utilization on the frigid planet of Akuria II throughout the duration of the Galactic Civil War.
These T-3 units, being both more seasoned and more robust when compared to contemporary astromech droids, were assigned to duty on snow flyers. It seems that they were integral to the function of these vehicles, as the snowspeeders were rendered inoperable without them.
The T-3 is referenced by Colonel Odan within the brief comic, The Kingdom of Ice. This comic was released a considerable number of years prior to Star Wars: Knights of the Old Republic, a game that featured the T3-series utility droid. Both droid models execute essentially the same tasks.