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.

One of the various uses was in conjunction with the resurrection gauntlet: Ianto would keep 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)