Defabricator

The defabricator was a device from the year 200,100. It was previously used by the Trin-E and Zu-Zana robots on the series upgraded version of "What Not to Wear" from the 21st century. Its original use was to "defabricate" clothing by making it literally disappear. Captain Jack Harkness was able to upgrade the device into a powerful weapon, by tweaking the system, after he destroyed the robots, who tried to kill him. The weapon fired a bluish beam of energy that was capable of piercing Dalekanium armour, and hence could destroy a Dalek. When a Dalek inadvertantly materialised onboard the TARDIS, Jack used the weapon to kill it, but this resulted in depleting the power source. (DW: Bad Wolf / The Parting of the Ways) Jack had somehow managed to have brought this weapon along with him and used the weapon again when the Earth was stolen by the Daleks. Apparently this time he had replaced the power source with a better one as he was able to use it at least twice; killing a Dalek and the Supreme Dalek. (DW: The Stolen Earth / Journey's End)

Behind the scenes

 * It is unknown if it was destroyed when the British Government destroyed Torchwood Three's base during the 456 incident. (TW: Children of Earth: Day One)