Burg "Sawmill" Houri discovered specimen 632 in one of the deeper chambers east of the Pits of the Rapacious Uberbeast.
The device's suitcase-sized voice controller connects wirelessly (via the controller's extensible "rabbit ear" antennae) to its pink-bubbling-nuclear-fluid-filled transparent, cylindrical power unit (12-ounce capacity). During operation, the controller makes "boop, boop... boop, boop..." noises, and the power supply sprays glowing dust into the air. The dust smells faintly of strawberries (long-term exposure not recommended).
Given a properly specified voice instruction, the devices alters two discrete events that occurred within the last 24 hours by switching two of the involved persons. Everyone remembers the events as they originally occurred, except for the two swapped individuals.