Suppression collar

The suppression collar was a device designed to prevent an individual from exercising their psionic abilities, inhibiting telepathy or psychokinesis. According to Quark, most telepathic suppressors were fairly bulky devices.

Eris, a Dominion spy, was supposedly fitted with a telekinetic suppression collar after her "capture" by the Jem'Hadar. In reality, this collar was little more than a collar with a complex locking device. (DS9: "The Jem'Hadar")

This device was not identified, aside from being a "collar", in dialogue, but was instead referred to as "Eris's suppression collar" in the script .