Device to be issued to CONTROL Agent 99 when she is assigned on a mission to transport a briefcase containing a half million dollar payroll to freelance agents behind the Iron Curtain.
The exact nature of the device is unknown. However, the name suggests a more violent solution to capture than the suicide pill.
In the event, 99's place on the mission is taken by Maxwell Smart after he accidentally handcuffs the briefcase to his own wrist with the only key being in the possession of the intended recipient.
[Mentioned, Episode #13: "Aboard the Orient Express".]