Stopwatch
A stopwatch was a type of watch used to measure the amount of time between the beginning and end of an event.
According to Ianto Jones, there were "many things you can do with a stopwatch". This apparently had sexual implications. Ianto often used his stopwatch in conjunction with the resurrection gauntlet, keeping track of how much time they had left until the victim would die again. (TV: They Keep Killing Suzie) Ianto appeared to carry a stopwatch on his person a lot of the time, and used it on another occasion to time the countdown of a Tregennan demolition bomb. (PROSE: Virus) Gwen Cooper once noted that he was "very fond" of his stopwatch. (PROSE: Plant Life)