Explosive Collar

The explosive collar is a piece of headwear in Fallout: New Vegas.

Gameplay
Most commonly used on slaves as an incentive to be obedient and not try to leave without a say-so. They explode via remote trigger, but will also explode if someone attempts to interfere with the collar's wiring as it will activate a self-destruct function.

Locations
The Brotherhood of Steel will force the Courier to equip one when they first meet in the Hidden Valley Bunker as a way to make sure the Courier does not reveal their location to the enemy (unless the Courier is accompanied by Veronica). The captives in Dead Money, as well as Mrs. Weathers and her two children, Kenny Weathers, and Sammy Weathers from the quest Left My Heart are also equipped with them.