Agonizer

An Agonizer

An Agonizer was a small device worn on the belts of Imperial personnel in the mirror universe, used to inflict pain for minor transgressions. More severe offenses called for using the Agony Booth. (TOS: "Mirror, Mirror")

In DS9: "Shattered Mirror", agonizers were seen as still being used in the mirror universe. They were sufficiently improved over the earlier model that they no longer needed physical contact with their victims to be effective.

In the primary universe, the Klingons also used a similar device in 2268. (TOS: "Day of the Dove")

In 2370, Arctus Baran used neural servos, which were implanted in each member of his crew, as a means of maintaining obedience. (TNG: "Gambit, Part I", "Gambit, Part II")

In 2372, in the Mirror Universe, Kira and Garak were subjected to these machines by their captors to make them more obedient. (DS9: "Shattered Mirror")

An Agonizer in use.