Gallifreyan Army knife

A Gallifreyan Army knife was a multipurpose tool issued to the Chancellery Guard. The Doctor had one which was marked as property of Castellan Spandrell.

The Sixth Doctor used his Gallifreyan Army knife to escape from a dungeon on Rigel VII. (PROSE: Players)

The Seventh Doctor used his Gallifreyan Army knife to open a transmat's control panel and later to cut Ace's bonds. (PROSE: Timewyrm: Exodus) During a visit to Gallifrey, he gave it back to Spandrell. (PROSE: Blood Harvest)