Obtained by Father Elijah at Little Yangtze during his investigation of the Big MT, these collars are more advanced than the more commonly seen slave collar due to Elijah's adjustments. He altered and improved them during his stay in the Big MT, so now they can be detonated remotely through a special radio frequency, as well as being programmed to detonate should other slave collars go inactive (due to the wearer's death). Because of these added features, Elijah finds the collars a perfect tool to get unsuspecting wanderers of the wastes to aid him in his efforts to break into the Sierra Madre Vault.
The collar is worn around the neck and provides a Damage Threshold of 3. It can be remotely detonated by Elijah should the wearer try to disobey his order, or attempt to escape the Sierra Madre. The collar can be set off by certain frequencies emitted by radios and speakers. Coming within 8 yards of a radio or 12 yards of a speaker will start a 10-second countdown; if the Courier does not leave the radius or disable the radio or speaker within that time the collar explodes, they will die instantly. If the Courier has Christine Royce as a companion, the countdown is extended by 5 seconds.
An additional feature of the collar is a dead man's switch function. This will detonate all collars within a specified group should one of those members die or be killed. The signal can, however, be blocked by Saturnite alloys.
Despite the radio signals presenting a time limit before the collar explodes, when in close proximity, it is possible to sleep in a bed for many hours while the collar is beeping.
As mentioned by Elijah on his radio frequency, the Courier carries Collar 21.
