Sonic blaster

The sonic blaster was a weapon and tool used by Captain Jack Harkness, one of many pieces of advanced technology he brought to the year 1941. The Doctor noted that the factory where it was manufactured later became the site of a banana grove. (DW: The Doctor Dances)


 * By implication, Jack brought the blaster from his own time, in the 51st century, though he does not directly say so.

Abilities
The blaster used a sonic wave projected into the form of pulsing squares of blue light which could cut through thick walls, and also had a reverse function which could replace the removed chunk of material afterwards.The only problem is that it runs on batteries (DW: The Doctor Dances)


 * Jack explained that the blaster used digital technology, so by implication, the blaster could encode the molecules of the destroyed materials and re-integrate them from the same source.

The Doctor switches Jack's sonic blaster with a banana at one point (DW: The Doctor Dances).