Communicator

Communicators are quest items in Sonic Chronicles: The Dark Brotherhood. They were developed by Doctor Eggman, responding only to a special frequency used by the doctor.

Description
Sometime after Eggman was presumed dead, Marauder Scouts used these communicators to keep in touch with their base. In Sonic Chronicles: The Dark Brotherhood, when Sonic and his friends were searching for Knuckles in Eggman's old hideouts, they found a communicator in each of the four abandoned hideouts. After the team had found Knuckles, Tails rewired the four communicators they had found, reversing them in order to detect the special frequency they used to operate. The resulting tracker was the Eggman Detector, which was used to find Eggman's secret base on Green Hill Zone