Machine That Goes "Ding"

A Machine That Goes "Ding" was a machine that the Tenth Doctor used to detect Zygon DNA in The Day of the Doctor.

Trivia

 * As stated by the Tenth Doctor, besides lighting up when in the presence of a Zygon, the machine can microwave frozen dinners from up to 20 feet and also download comics from the future.
 * Though the Doctor thought it was Elizabeth I that was the Zygon, it turned out to be their Horse instead.
 * He thought it was Elizabeth because she would never accept his marriage proposal and she would've noticed when he "casually" mentioned having another face.
 * The machine often malfunctioned, so it is unknown if the Doctor still has it in his possession.