Slave collar

The Slave Collar is a Collar used by the Slavers from Paradise Falls. It is said that the collars send out a frequency to Paradise Falls and keep track on where every collar is located. The Collar is equipped with explosives and is set off as soon as a Slave tries to escape.

Grouse keeps track of all Collars.

The Player Character recieves a Slave Collar and a Mesmetron for use in the Quest Strictly Business.

--An unknown glitch may occur during the Strictly Business quest in which Grouse will present the player more than one collar at a time.

Related Quests
Strictly Business

Trivia
The Mesmetron is similar to the Persuadatron from the Syndicate game series, going as far to even being named similar. The Persuadatron on the other hand allowed complete domination over a victim without the need of a Slave Collar.

The idea of an exploding Slave Collar is featured in quite a few movies and novels. Such as:

The Running Man where people are held captive through the use of collars around thier necks that can be triggered to explode.

Another film making use of an "exploding collar" to make prisoners obey is Wedlock. Also widely known as Deadlock.

Exploding collars are also used in the movies Battle Royale and Battle Royale 2: Requiem.