The Traveler communicator is a piece of technology used by the Travelers for communication.
Made by the Travelers, the device is used for communication with each other over distances, and is attached to an armband.
In 2007, when John Sheppard was kidnapped by the Travelers and taken on board a Lantean Aurora-class battleship, he was forced to fly the ship. He was able to disarm his captors and took one of the communicators. (SGA: "Travelers")