Transphasic torpedo

The transphasic torpedo was a Starfleet weapon developed sometime in the 2380s in a future alternate timeline. It was designed specifically to handle the Borg threat, with input by Captain Kathryn Janeway and the crew of the USS Voyager.

In 2378, the point to which Admiral Janeway from the alternate timeline had traveled back in time, the admiral introduced Captain Janeway to this technology for use in reaching a Borg transwarp hub accessing the Borg transwarp network to return to Earth. When entering the nebula where the transwarp hub was located, one transphasic torpedo was enough to destroy a Borg cube. Despite the use of transphasic torpedoes to destroy two cubes, the Collective had not yet adapted to the torpedoes when Voyager fired at the interspatial manifolds in the transwarp network. (VOY: "Endgame")

After their critical role in "Endgame", transphasic torpedoes were not shown or mentioned in Star Trek Nemesis.